HomeMy WebLinkAboutC2. CM Sign Memorandum
Commission Memorandum
REPORT TO: Honorable Mayor and City Commission
FROM: Brian Heaston, Project Engineer Craig Woolard, Public Works Director
SUBJECT: Authorize the City Manager to sign Memoranda of Agreement with the Gallatin Local Water Quality District, Montana Conservation Corps, and MSU Extension Water Quality as well as PSA
Amendment No. 7 with HDR Engineering in connection with project WW27 of the approved FY 17
Wastewater Fund CIP.
MEETING DATE: April 11, 2016 AGENDA ITEM TYPE: Consent
RECOMMENDATION: Authorize the City Manager to sign Memoranda of Agreement with the
Gallatin Local Water Quality District, Montana Conservation Corps, and MSU Extension Water Quality
as well as PSA Amendment No. 7 with HDR Engineering in connection with project WW27 of the approved FY 17 Wastewater Fund CIP.
BACKGROUND: The approved FY 17 Wastewater Fund CIP contains $200,000 for project WW27, a watershed study and stream modeling project for the East Gallatin River. The city intends to utilize a
fully calibrated and verified water quality model to derive specific numeric nutrient limits for the East
Gallatin River. The model will serve as an important tool that will inform wastewater discharge permit compliance discussions with the DEQ. The FY 17 effort builds upon work completed in the previous two
fiscal years to collect water quality data in accordance with sampling guidelines provided by the DEQ. The city is partnering with the Gallatin Local Water Quality District (GLWQD) to lead the data collection effort similar to the previous two years. Additional partnerships are necessary with the Montana
Conservation Corps (MCC) and MSU Extension Water Quality (MSUEWQ) to provide qualified field personnel necessary to complete the sampling field work. Separate Memoranda of Agreement with GLWQD, MCC, and MSUEWQ area attached. Each outlines the particular roles and responsibilities of
the parties as well as costs. Water quality data collected over the past two years as well as data to be collected this coming summer season will be utilized by HDR Engineering to calibrate and validate a
water quality model for the East Gallatin River. The PSA Amendment attached provides scope and fee to
complete the model as well as wastewater discharge permitting assistance.
UNRESOLVED ISSUES: None.
ALTERNATIVES: As suggested by the City Commission.
FISCAL EFFECTS: The approved FY17 Wastewater Fund CIP contains $200,000 for project WW27. Total planned costs in the MOAs and PSA Amendment are broken out below and amount to $201,250.
Adequate funding exists within the remaining FY16 WRF Plant budget for professional services and the adopted CIP budget for project WW27 to cover the $201,250 total planned cost.
10
• MOA w/GLWQD costs: $93,950 (all in FY17)
• MOA w/MCC costs: $12,000 (all in FY17)
• MOA w/MSUEWQ costs: $4,300 (all in FY17)
• PSA Amendment No. 7 w/ HDR Engineering costs: $91,000 ($6,000 to $11,000 in FY16 and
$80,000 to $85,000 in FY17)
Attachments: MOA w/GLWQD MOA w/MCC
MOA w/MSUEWQ PSA Amendment No. 7 w/HDR Engineering
Report compiled on: March 31, 2016
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FY2017 MOA for East Gallatin River Water Quality Sampling Page | 1
MEMORANDUM OF AGREEMENT
Between
CITY OF BOZEMAN
And
GALLATIN LOCAL WATER QUALITY DISTRICT
For
FY2017 EAST GALLATIN RIVER WATER QUALITY SAMPLING
This Memorandum of Agreement (this ‘Agreement’) made this day of , 2016,
between the CITY OF BOZEMAN, a municipal corporation of the State of Montana (COB) and
the GALLATIN LOCAL WATER QUALITY DISTRICT (GLWQD), describes the duties, agreements
and obligations of the COB and GLWQD in connection with water quality sampling and analysis
on the East Gallatin River.
Article 1 – Roles and Responsibilities
A) GLWQD agrees to perform water quality sampling activities on the East Gallatin River in
general accordance with ‘Appendix A: Recommendations for Sampling and Modeling the
East Gallatin River to Accomplish Multiple Objectives’ (hereafter ‘Sampling Effort’)
contained in Version 1.0 of the Base Numeric Nutrient Standards Implementation Guidance
developed by the Montana Department of Environmental Quality (DEQ) hereby
incorporated by referenced and attached to this Agreement. More specifically, the
following tasks will be performed by GLWQD to support development of a mechanistic
water quality model (to be completed by others) for the East Gallatin River between Bridger
Creek and West Gallatin River confluences to be utilized in deriving reach-specific nitrogen
and phosphorous criteria:
1) GLWQD agrees to prepare a Sampling and Analysis Plan (SAP) to document activities
to be conducted for the Sampling Effort during the 2016 field season. The SAP will
be presented to the COB and DEQ for review and approval. Any changes to the
approved SAP necessitated by field conditions or other circumstances will be
documented by Addendum to the SAP.
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FY2017 MOA for East Gallatin River Water Quality Sampling Page | 2
2) Acquire data necessary to complete the Objective described in Section A3.0 of the
Sampling Effort sufficient to calibrate and confirm a mechanistic model of the study
reach.
a) Sampling at six sites (A, D, G, H, I, and J) as recommended in Section A3.1 of
the Sampling Effort, will be performed in August 2016. Water quality
sampling will be synoptic and occur within a 1 or 2-day period. Biological
data (benthic algae and phytoplankton) will be sampled immediately
following. Sampling activities will acquire the following data, be documented
in the SAP prepared per Article 1.A.1 of this Agreement, and be designed to
sample for key model drivers contained in Section A3.1 of the Sampling
Effort.
1) Benthic Algae (Chlorophyll-a)
2) Benthic Algae (Ash-Free Dry Mass)
3) Phytoplankton (Chlorophyll-a)
4) Water Quality: Nutrients (TN, TP, SRP, nitrate + nitrite, total
ammonia), TSS, ISS, alkalinity, hardness, TOC, CBOD20
5) Stream discharge
6) PAR
7) Instantaneous field parameters (DO, pH, SC, water temperature)
8) Collect data from sondes deployed at each of the 6 sites (A, D, G, H, I,
and J) for a minimum of 14 days in August 2016. Water-quality
parameters to be measured include DO (DO delta), pH, temperature,
conductivity and turbidity.
b) Sampling at additional sites as generally recommended in Section A3.2 of the
Sampling Effort, will be performed in August 2016 and September 2016.
Water quality sampling will be synoptic and occur within a 1 or 2-day period.
Biological data (benthic algae and phytoplankton) will be sampled
immediately following. Sampling activities will acquire the following data, be
documented in the SAP prepared per Article 1.A.1 of this Agreement, and be
designed to sample for key model drivers contained in Section A3.1 of the
Sampling Effort.
1) Benthic Algae (Chlorophyll-a)
2) Benthic Algae (Ash-Free Dry Mass)
3) Phytoplankton (Chlorophyll-a)
4) Water Quality: Nutrients (TN, TP, SRP, nitrate + nitrite, total
ammonia), TSS, ISS, alkalinity, hardness, TOC, CBOD20
5) Stream discharge
6) PAR
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FY2017 MOA for East Gallatin River Water Quality Sampling Page | 3
7) Collect instantaneous data for: DO, pH, conductance, and
temperature
B) GLWQD agrees to use laboratories and equipment recognized by DEQ to produce data of
sufficient quality for the intended purpose of the Sampling Effort and to process data as
appropriate and input into the state’s official water quality database.
C) GLWQD agrees to manage and direct field work activities of personnel representing other
organizations that assist the COB, by way of separate Memorandum of Agreement, with the
East Gallatin River water quality sampling effort.
D) The COB agrees to fund laboratory costs, equipment rental costs, labor costs, and GLWQD
professional services costs to the complete the Sampling Effort in accordance with Article 2
below.
Article 2 – Payment Schedule
A) Laboratory and equipment rental and/or equipment purchase invoices will be paid by the
COB directly. A cost not to exceed $50,000 is provided for lab analyses and equipment
rentals. A project analytical budget for lab and equipment rentals and/or equipment
purchase costs shall be prepared by GLWQD and included in the SAP.
B) The COB will pay GLWQD for professional services costs for SAP preparation, lab and
equipment vendor coordination, obtaining site access permissions, and field work at a total
unit cost of $750/site-visit for a total cost not to exceed $33,750. The COB agrees to pay
these professional services costs upon presentation of invoices from the GLWQD.
C) The COB will pay GLWQD for professional services costs for data processing and data entry
into the state’s water quality database at a unit cost of $600/site for a total cost not to
exceed $10,200. The COB agrees to pay these professional services costs upon presentation
of invoices from the GLWQD.
Article 3 – Duration of the Agreement
The term of this agreement shall expire on June 30, 2017 unless separately extended or
amended as agreed by the parties hereto.
Article 4 – Independent Contractor
The parties agree that GLWQD is an independent contractor for purposes of this Agreement
and is not to be considered an employee of the COB for any purpose. Neither GLWQD nor any
of its employees, officials, or agents, are subject to the terms and provisions of the COB’s
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FY2017 MOA for East Gallatin River Water Quality Sampling Page | 4
personnel policies handbook and may not be considered a COB employee for workers’
compensation or any other purpose. GLWQD is not authorized to represent the COB or
otherwise bind the COB in any dealings between GLWQD and any third parties.
Article 5 – Non-Discrimination
GLWQD will not refuse employment to a person, bar a person from employment, or
discriminate against a person in compensation or in a term, condition, or privilege of
employment because of race, color, religion, creed, political ideas, sex, age, marital status,
national origin, actual or perceived sexual orientation, gender identity, physical or mental
disability.
Article 6 – Execution
IN WITNESS WHEREOF, the parties have caused this Agreement to be executed by their
authorized representatives, on the day and year first written above.
CITY OF BOZEMAN
(Signature)
City Manager
(Title)
Chris Kukulski
(Printed Name)
APPROVED AS TO FORM:
GREG SULLIVAN, CITY ATTORNEY
GALLATIN LOCAL WATER QUALITY DISTRICT
(Signature)
Board Chair
(Title)
Kathy Gallagher
(Printed Name)
15
WQPBWQSTR-002
Base Numeric Nutrient Standards
Implementation Guidance
Version 1.0
JULY 2014
Prepared by:
Water Quality Planning Bureau, Water Quality Standards Section
Montana Department of Environmental Quality
1520 E. Sixth Avenue
P.O. Box 200901
Helena, MT 59620-0901
16
Suggested citation: Montana Department of Environmental Quality, 2014. Base Numeric Nutrient
Standards Implementation Guidance. Version 1.0. Helena, MT: Montana Dept. of Environmental Quality
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Base Numeric Nutrient Standards Implementation Guidance – Table of Contents
7/31/14 Final i
TABLE OF CONTENTS
Acronyms ...................................................................................................................................................... v
1.0 Introduction ............................................................................................................................................ 1
1.1 Scope ................................................................................................................................................... 1
1.2 Definitions ........................................................................................................................................... 1
2.0 Defined Nutrient-reduction Steps for Permittees Operating under a General Nutrient Standards
Variance ........................................................................................................................................................ 1
3.0 Guidance Pertaining to the Evaluation Process for Individual Variances ............................................... 2
3.1 Public-sector Permittees ..................................................................................................................... 2
3.1.1 Substantial and Widespread Economic Impacts: Process Overview ........................................... 3
.................................................................................................................................................................. 3
3.1.2 Completing the Substantial and Widespread Assessment Spreadsheet ..................................... 5
3.1.3 The Remedy: Determining the Target Cost of the Pollution Control Project .............................. 6
3.2 Private-sector Permittees ................................................................................................................... 8
3.2.1 Substantial and Widespread Economic Impacts: Process Overview ........................................... 9
3.2.2 Completing the Substantial and Widespread Assessment Spreadsheet ................................... 10
3.2.3 The Remedy: Determining the Cost of the Pollution Control Project for Private Entities ......... 10
4.0 Guidelines for Developing Individual Nutrient Standards Variances via Water Quality Modeling, and
the Relation of these to Site-specific Numeric Nutrient Criteria ................................................................ 11
4.1 Mechanistic and Empirical Modeling Approaches for Establishing Reach-specific Nutrient
Standards and Individual Variances (If Necessary) ................................................................................. 12
4.2 Protection of Downstream Beneficial Uses ...................................................................................... 13
4.3. Unwarranted Cost and Economic Impact ........................................................................................ 13
4.4 Periodic Review of the Individual Variance, Board Adoption of Site-specific Criteria ...................... 14
5.0 Guidance Pertaining to Alternative Nutrient Standards Variances ...................................................... 15
6.0 Streamlined Methods for Developing Site-specific Numeric Nutrient Criteria .................................... 16
6.1 Background and Rationale ................................................................................................................ 16
6.2 Site-specific Methods ........................................................................................................................ 16
6.2.1 Two Site-specific Methods ......................................................................................................... 17
6.2.2 Other Methods ........................................................................................................................... 19
6.3 Confirmation of Biological Health, and Minimum Dataset ............................................................... 20
6.3.1 Assessment of the Biological Health of the Stream ................................................................... 20
6.3.2 Dataset Minimum ...................................................................................................................... 20
6.3.3 Consideration of the Other Nutrient ......................................................................................... 21
6.4 Case-study Example .......................................................................................................................... 21
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Base Numeric Nutrient Standards Implementation Guidance – Table of Contents
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6.4.1 Data Summary for Stream X (in Middle Rockies Ecoregion) ...................................................... 21
6.4.2 The Assessment of Stream X ...................................................................................................... 22
6.4.3 Site-specific Criteria Derivation for Stream X using the Streamlined Approach........................ 22
Appendix A: Recommendations for Sampling and Modeling the East Gallatin River to Accomplish
Multiple Objectives ..................................................................................................................................... 23
A1.0 Background ......................................................................................................................................... 23
A1.1 Design and Possible Outcomes of the Investigation ...................................................................... 23
A1.2 Summary of the Basic Approaches to Reach-specific Criteria ........................................................ 25
A2.0 Biological Characterization of the East Gallatin River, and the Empirical Model Approach to Deriving
Reach-specific Criteria ................................................................................................................................ 26
A2.1 Detailed Consideration of the Objective 1 ..................................................................................... 26
A2.2 Data Collection Methods ................................................................................................................ 29
A2.3 Recommended Sampling Sites along the East Gallatin River ......................................................... 29
A2.4 Sampling Frequency and Duration of Study ................................................................................... 31
A2.5 Data Analysis and Interpretation .................................................................................................... 35
A2.6 Reach Specific Criteria—Empirical Approach ................................................................................. 35
A2.7 Protection of Downstream Uses ..................................................................................................... 35
A3.0 Developing Reach Specific Criteria via the Mechanistic Modeling Approach .................................... 36
A3.1 Sites Requiring Water Quality Sonde Deployment ......................................................................... 37
A3.2 Additional Sites Requiring Flow and Water Quality Data ............................................................... 39
A3.3 Other Data ...................................................................................................................................... 40
A3.4 Numeric Nutrient Criteria Derivation Process via QUAL2K ............................................................ 40
A4.0 Can Beneficial Uses be Supported by Applying Greater Emphasis on Reducing One Nutrient? ........ 40
A5.0 Status Monitoring ............................................................................................................................... 42
A6.0 Budget Estimates ................................................................................................................................ 42
A7.0 Next Steps ........................................................................................................................................... 43
Appendix A1 ................................................................................................................................................ 44
Document and Appendix References ......................................................................................................... 47
LIST OF FIGURES
Figure 3-1. Flow chart for evaluation of substantial and widespread economic impacts ............................ 3
Figure 3-2. Sliding scale for determining cost cap based on a community’s secondary score. .................... 7
Figure 6-1. Overview of the Streamlined Site-specific Criteria Methods. .................................................. 17
Figure 6-2. Scenario 1. Candidate site-specific nutrient criteria may fall between the ecoregional nutrient
standard (black dot with X) and the 95th percentile of the applicable reference distribution (dashed
arrow). ......................................................................................................................................................... 18
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Base Numeric Nutrient Standards Implementation Guidance – Table of Contents
7/31/14 Final iii
Figure 6-3. Scenario 2. Site-specific criteria derivation method for cases where a Department-
recommended criterion is near or above the 95th percentile of the ecoregional reference distribution. . 19
Figure A1-1. Flowchart outlining various outcomes from the analysis of reach-specific data and the
development of reach-specific criteria. ...................................................................................................... 24
Figure A2-1. Ten biological and water quality sampling sites along the East Gallatin River. ..................... 32
Figure A2-2. Sampling sites A to G along the East Gallatin River between the Bridger and Hyalite creek
confluences. ................................................................................................................................................ 33
Figure A2-3. Close-up of the three sampling sites around the city of Bozeman WRF discharge. Green dot
is USGS gage 06048700. .............................................................................................................................. 34
Figure A3-1. Map showing the six main sites along the East Gallatin River needed for the development of
the QUAL2K model. ..................................................................................................................................... 38
Figure A4-1. QUAL2K model results for nitrogen, phosphorus, and light limitation of benthic algae in the
Yellowstone River. From Flynn and Suplee (2013). .................................................................................... 41
LIST OF TABLES
Table A2-1. Discharge, ft3/sec for USGS Station 06048700 "East Gallatin River at Bozeman, Mont.". Mean
of daily values for 10 years of record (calculation period 2001-10-01 to 2011-09-30). ............................. 26
Table A1-1. Biological Characterization (2-year study, up to three months per summer). This work is
undertaken regardless of preferred modeling approach. .......................................................................... 44
Table A1-2. Statistical Empirical Model (One additional year of data in additional to the biological
characterization). ........................................................................................................................................ 45
Table A1-3a. QUAL2K Model main sites (data in addition to data from the biological characterization).
Assumes a single year sampling in Aug and Sept. ...................................................................................... 45
Table A1-3b. QUAL2K Model, Additional Sites. Assumes a single year sampling in Aug and Sept. ........... 46
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Base Numeric Nutrient Standards Implementation Guidance– Acronyms
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ACRONYMS
Acronym Definition
AFDM Ash Free Dry Mass
CBOD20 Carbonaceous Biochemical Oxygen Demand, run for 20 consecutive days
DEQ Department of Environmental Quality (Montana)
DO Dissolved Oxygen
EMAP Environmental Monitoring and Assessment Program
EPA Environmental Protection Agency (U.S.)
EPT Ephemeroptera, Plecoptera, and Trichoptera
HBI Hilsenhoff Biotic Index
ISS Inorganic Suspended Sediment
LMI Low to Moderate Income
MCA Montana Code Annotated
MHI Median Household Income
PAR Photosynthetically Active Radiation
QAPP Quality Assurance Project Plan
SAP Sampling and Analysis Plan
TMDL Total Maximum Daily Load
TN Total Nitrogen
TOC Total Organic Carbon
TP Total Phosphorus
TSS Total Suspended Solids
USGS United States Geological Survey
WRF Water Reclamation Facility
WWTP Wastewater Treatment Plant
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Base Numeric Nutrient Standards Implementation Guidance
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1.0 INTRODUCTION
This document was developed through the collective efforts of the Nutrient Work Group and the
Department. It provides guidance pertaining to the implementation of Montana’s base numeric nutrient
standards and variances from those standards. The remaining sections address the following topics:
Section 2.0: For permittees operating under a general nutrient standards variance, this section provides
the defined effluent limits (i.e., nutrient reduction steps) to be met over several permit cycles of the
general variance.
Section 3.0: Provides guidance for the development of individual nutrient standards variances for public-
and private-sector entities, based on economic factors and the limits of technology.
Section 4.0: Provides detailed, data-intensive modeling approaches for developing site-specific numeric
nutrient criteria. This approach lends itself to the development of model-based individual variances for
dischargers.
Section 5.0: Provides guidance for the development of alternative nutrient standards variances for
public- and private-sector entities.
Section 6.0: Outlines a streamlined approach for developing site-specific numeric nutrient criteria for
streams or rivers where full biological support is demonstrated but where the existing nutrient
concentrations exceed applicable base numeric nutrient standards.
1.1 SCOPE
The provisions for general, individual, and alternative variances in section 75-5-313, Montana Code
Annotated (MCA), are available to all discharge permit holders and are not limited to dischargers under
permit on the effective dates of Department of Environmental Quality (DEQ) Circular DEQ-12A or DEQ
Circular DEQ-12B.
1.2 DEFINITIONS
1. Limits of technology means treatment for the removal of nitrogen and phosphorus compounds
from wastewater that meets the more stringent of the following: (a) ability to consistently
achieve a concentration of 70 µg Total Phosphorus (TP)/L and 4,000 µg Total Nitrogen (TN)/L, or
(b) the best demonstrated control technology, processes, or operating methods available at the
time the Department evaluates a permittee’s application for a limits of technology variance.
2. Pollution control project means an upgrade to a wastewater treatment facility and all directly
relevant infrastructure.
2.0 DEFINED NUTRIENT-REDUCTION STEPS FOR PERMITTEES OPERATING
UNDER A GENERAL NUTRIENT STANDARDS VARIANCE
The Department and the Nutrient Work Group developed a series of defined nutrient-reduction steps to
be taken over time and that are specific to recipients of general nutrient standards variances. Per §75-5-
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Base Numeric Nutrient Standards Implementation Guidance
7/31/14 Final 2
313 [8], MCA, general nutrient standards variance may be established for no more than 20 years. The
intent of establishing nutrient reduction steps upfront for most of the 20 year period is to provide
permittees regulatory certainty well out into the future. This in turn allows for better facility planning
and financing. State law still requires the Department to review triennially the general variance
concentrations, and to lower them conforming with technological advancements and improvements in
cost (Montana Code Annotated (MCA) 75-5-313[7][b]). However, the Department will only supersede
the reduction steps defined here if substantial cost reductions for existing technology have occurred, or
technological innovations have allowed for nutrient reductions well beyond the defined steps and those
technologies can be readily implemented on wastewater facilities in Montana.
For the purposes of permit development, the values provided below apply to recipients of general
nutrient standards variances and the concentrations should be viewed as monthly averages applicable
during the time period the base numeric nutrient standards are in effect.
1. For facilities > 1 million gallons per day:
A. By 2016 (or first receipt of general nutrient standards variance): 10 mg TN/L, 1.0 mg TP/L
B. Next permit cycle (5 year later): 8 mg TN/L, 0.8 mg TP/L
C. Next permit cycle (5 years later): 8 mg TN/L, 0.5 mg TP/L
D. Next permit cycle (5 years later): Under Development
2. For facilities < 1 million gallons per day:
A. By 2016 (or first receipt of general nutrient standards variance): 15 mg TN/L, 2.0 mg TP/L
B. Next permit cycle (5 year later): 12 mg TN/L, 2.0 mg TP/L
C. Next permit cycle (5 years later): 10 mg TN/L, 1.0 mg TP/L
D. Next permit cycle (5 years later): 8 mg TN/L, 0.8 mg TP/L
3. For lagoons not designed to actively remove nutrients:
A. By 2016 (or first receipt of general nutrient standards variance): Maintain current lagoon
performance and commence nutrient monitoring in the effluent
B. Next permit cycles (5 years later): Implement BMPs identified during optimization study
3.0 GUIDANCE PERTAINING TO THE EVALUATION PROCESS FOR
INDIVIDUAL VARIANCES
Section 3.0 provides guidance on applying for an individual variance based on the direct evaluation of
economic factors. Section 3.1 applies to the public sector, while Section 3.2 applies to the private
sector.
3.1 PUBLIC-SECTOR PERMITTEES
Montana law allows for the granting of nutrient standards variances based on the specific economic and
financial conditions of a permittee (§75-5-313 (1), MCA). These variances, referred to as individual
nutrient standards variances (“individual variances”), may be granted on a case-by-case basis because
the attainment of the base numeric nutrient standards is precluded due to economic impacts, limits of
technology, or both. Individual variances may only be granted to a permittee after the permittee has
made a demonstration to the Department that adverse, significant economic impacts would occur, the
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Base Numeric Nutrient Standards Implementation Guidance
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limits of technology have been reached, or both, and that there are no reasonable alternatives to
discharging into state waters. The processes by which the demonstration is made are provided here, and
were developed in conjunction with Montana Nutrient Work Group.
Methods outlined below in Section 3.1.1 are Montana’s modifications to methods presented in U.S.
Environmental Protection Agency (1995; Montana Code Annotated (MCA) 75-5-513[7][b]) and pertain to
the economic impacts rationale for an individual variance. If adverse, substantial and widespread
economic impacts to a community trying to comply with base numeric nutrient standards can be
demonstrated, the facility interim effluent limit will be determined via a sliding scale as proposed by
Environmental Protection Agency (EPA) in its September 10, 2010 memo to the Department entitled
“EPA Guidance on Variances”.
Permittees applying for an individual variance based on discharging at the limits of technology do not
have to prepare the economic analysis presented below in Section 3.1.1. Rather, they should
demonstrate to the Department that the waste treatment system they are proposing can achieve, at a
minimum, the nitrogen and phosphorus concentrations described in Section 1.2 of this document, and
that achieving those concentrations still will not enable them to attain the base numeric nutrient
standards at a 14Q5 flow. Various factors will have a bearing on the final effluent concentrations
approved by the Department for individual variances discussed in this paragraph.
3.1.1 Substantial and Widespread Economic Impacts: Process Overview
The Department has assumed that most permittees who cannot comply with the base numeric nutrient
standards (Montana Department of Environmental Quality, 2014a) would pursue a general variance
(Montana Department of Environmental Quality, 2014b). Therefore, individual variances discussed here
are generally for permittees for whom significant economic impacts would occur even at the general
variance treatment levels. As noted above, the Department will assess economic impacts using a
modified version of EPA’s economic-impact guidance. For communities with secondary scores (discussed
further below) of 1.5 or lower, the cost cap for the upgrade would be set at 1.0% or lower of the median
household income (MHI) for a community, including existing wastewater fees. If the cost cap were
below existing wastewater rates, then no further action would be required. Higher Secondary scores
would to a higher MHI cost cap. See Figure 3-1 for a small flow chart of the overall process.
Figure 3-1. Flow chart for evaluation of substantial and widespread economic impacts
The following is an overview of the steps required to carry out a substantial and widespread economic
analysis for a public-sector permittee. The evaluation can be undertaken directly in an Excel spreadsheet
Can the
permittee
affordably
meet the
General
Variance?
Permittee meets the General Variance with upgrades or optimization
Permittee
applies for an
Individual
Variance.
Permittee
demonstrates they
cannot meet base
nutrient standards
using significant and
widespread tests.
After looking at all
alternatives to meeting the
base numeric nutrient
standards, permittee takes
Secondary Score and uses
sliding scale to determine
cost cap. Permittee works
with the Department to find
a variance solution based on
the cap.
NO
YES
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Base Numeric Nutrient Standards Implementation Guidance
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template which contains instructions. The template is called
“PublicEntity_Worksheet_EPACostModel_2014.xlsx”, and is available from the Department.
Step 1: Verify project costs that would occur from meeting the base numeric nutrient standards and
calculate the annual cost of the new pollution control project.
Step 2: Calculate total annualized pollution control cost per household including existing wastewater
fees and the new pollution control project (manifested as an increase in the household
wastewater bill).
Steps 3-5: The Substantial Test
Step 3: Calculate and evaluate the Municipal Preliminary Screener score based on the new wastewater
fees and the town’s Median Household Income. This step identifies communities that can
readily pay for the pollution control project vs. those that cannot.
Note: If the public entity passes a significant portion of the pollution control costs along to private
facilities or firms, then the review procedures outlined in Chapter 3 of U.S. Environmental Protection
Agency 1995 (EPA, (1995) for 'Private Entities' should also be consulted to determine the impact on the
private entities.
Step 4: Calculate the Secondary Test to get a secondary score. This measurement incorporates a
characterization of the socio-economic and financial well-being of households in the community
where the wastewater plant is located. It comprises five evaluation parameters which are then
compared against state averages for a score. The scores of the five parameters are averaged to
provide the secondary test score for a given community. A secondary score can range from 1.0
to 3.0. A value of 3.0 is a strong score and 1.0 is a weak score.
Note: The Secondary Score is based on the assumption that the ability of a community to finance a
project may be dependent upon existing household financial conditions within that community.
Step 5: Assess where the community falls in the substantial impacts matrix. This matrix evaluates
whether or not a given community is expected to incur substantial economic impacts due to the
implementation of the pollution control costs. If the applicant can demonstrate substantial
impacts, then the applicant moves on to the widespread test. If the applicant cannot
demonstrate substantial impacts, then they will not perform the widespread test; they will be
required to meet the base numeric nutrient standards.
Note: The evaluation of substantial impacts resulting from compliance with base numeric nutrient
standards includes two elements; (1) financial impacts to the public entity as measured in Step 3
(reflected in increased household wastewater fees), and (2) current socio-economic conditions of the
community as measured in Step 4. Governments have the authority to levy taxes and distribute
pollution control costs among households and businesses according to the tax base. Similarly, sewage
authorities charge for services, and thus can recover pollution control costs through user’s fees. In both
cases, a substantial impact will usually affect the wider community. Whether or not the community
faces substantial impacts depends on both the cost of the pollution control and the general financial and
economic health of the community.
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Step 6: The Widespread Test
Step 6: If impacts from meeting the base numeric nutrient standards are expected to be substantial,
then the applicant goes on to demonstrate whether or not the impacts are expected to be
widespread. The Widespread test consists of questions that ask the permittee about current
economic, social and population trends in the affected area (usually the community and possibly
outlying areas tied to the community). The permittee is then asked to estimate the effects of
higher wastewater costs on each of these trends. Further optional questions are asked about
the effects of higher wastewater costs on things like city debt limits, improved water quality,
future development patterns, and other factors that the applicant may want to add.
Note: Estimated changes in socio-economic indicators of the community and other geographical areas
tied to the community as a result of pollution control costs will be used to determine whether
widespread impacts would occur.
Step 7: Final Determination of Substantial and Widespread Economic Impacts
Step 7: If widespread impacts are also demonstrated, then a permittee is eligible for an individual
variance after having demonstrated to the Department that they considered alternatives to
discharging (including but not limited to trading, land application, and permit compliance
schedules). If widespread impacts have not been demonstrated, then the permittee is not
eligible for an individual variance based on these methods.
3.1.2 Completing the Substantial and Widespread Assessment Spreadsheet
Detailed steps for completing the substantial and widespread cost assessment are found in the
spreadsheet template “PublicEntity_Worksheet_EPACostModel_2014.xlsx” available from the
Department and on the Nutrient Workgroup website. Readers should refer to that spreadsheet, as it is
self-explanatory and instructions are found throughout. Below are a few additional details which may
help clarify some of the steps:
1. Start at the far left tab of the spreadsheet (“Instructions [Steps to be Taken]”) and review the
instructions. They are the same steps outlined in Section 3.1.1 above, but in more detail.
Proceed to subsequent tabs to the right, making sure not to skip any of worksheets A through F.
2. Summarize the project on Worksheet A.
3. Detail the costs of the project on Worksheet B.
4. Calculated the annual cost per household of existing and expected new water treatment costs
on Worksheet C.
5. On Worksheet D, carefully read the text in blue and compare it to the results from the MHI test
and the community’s Low to Moderate Income (LMI) level. Based on this screener, the
evaluation will either terminate (i.e., it has been shown that the water pollution control is
clearly affordable), or will continue to the secondary tests on the next tab which is Worksheet
E1.
1 The Department appended the LMI test to EPA’s Municipal Preliminary Screener at this step in the process. This
was done in order to address communities in which the income distribution is skewed such that there is a large
proportion of high- and low-income individuals, but less in the middle near the median household income. As
modified, the test should assure that such communities will move on to the more detailed secondary tests.
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6. On Worksheet E, note the linkages to websites and phone numbers where the information
requested can be obtained. Then use this information to fill in Worksheet F where a secondary
score is calculated.
7. The next tab, ‘Substantial Impacts Matrix’, shows if the community has demonstrated
substantial impacts (or not). Those that have clearly demonstrated substantial impacts as well as
those that are ‘borderline’ move on to the widespread tests.
8. On the ‘DEQ Widespread Criteria’ tab, complete the four descriptive questions. Then, complete
the six primary questions and determine the outcome as to whether impacts are widespread. If
still unclear, complete the additional secondary questions and again evaluate.
9. In order to be eligible for an individual variance, both substantial and widespread tests must be
satisfied.
10. If substantial and widespread impacts are demonstrated, then the permittee moves on to the
next tab, Worksheet I, Remedy. In this step, the permittee examines and reports whether there
are “reasonable alternatives” to the individual variance that preclude the need for an individual
variance. If not, then then the cost the permittee will need to expend towards the pollution
control project will be based on the sliding scale (see below). The cost cap is determined as a
percentage of the community’s MHI, and the key driver of the required cost cap is the
Secondary Score.
The difference between the cost cap MHI from the sliding scale and what is currently being paid (also in
MHI) is the additional money that can go towards the pollution control project. Once the amount of
money available is determined, the Department and the applicant will look at both capital and O&M
investments that could be used to craft an individual variance, given what money is available. Refer to
Section 3.1.3 below for more details on the remedy process.
3.1.3 The Remedy: Determining the Target Cost of the Pollution Control Project
If a permittee has demonstrated that substantial and widespread economic impacts would occur if they
were to comply with the base numeric nutrient standards, and there are no reasonable alternatives to
discharging (including trading, permit compliance schedules, general variances, alternative variances, or
alternative effluent management loading reduction methods such as reuse, recharge, or land
application), then the cost the permittee will need to expend towards the pollution control project will
be based on a sliding scale (Figure 3-2). The cost cap is determined as a percentage of the community’s
MHI, and the key driver of the cost cap is the secondary test (secondary score) calculated in step 4 of
Section 3.1.1.
For example, a community has demonstrated that substantial and widespread economic impacts would
occur from trying to comply with the base numeric nutrient standards, and there were no reasonable
alternatives to discharging. If the permittee’s average secondary score from the secondary tests was 1.5,
then the annual cost cap for the pollution control project (including current wastewater fees) would be
the dollar value equal to 1.0% of the community’s MHI at the time that the analysis was undertaken (see
blue line, Figure 3-2). This 1.0% would include existing wastewater costs plus the new, hypothetical
upgrades.
If this community was already paying ≥ 1.0% of community MHI for its wastewater bill, then no
additional monies would be spent on capital or O&M costs (and no additional upgrades would occur).
Still, additional improvements may still be expected. The facility’s current discharge nutrient
concentrations might become the basis of the community’s individual variance but the community must
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first look at optimization options such as operator training and use all tools available within their cost
cap to improve water quality. Once those are considered, the individual variance can be developed.
The difference between the cost cap MHI from the sliding scale and what is currently being paid in MHI
is the additional money that can go towards the pollution control project. This amount could be zero in
some cases, as in the example just given. This additional money is calculated for the whole community
over 20 years (assumed life of the pollution control project) in order to see what the total amount of
money available would be. The cost cap, which is given as a percentage of a community’s MHI and
determined by the ‘sliding scale’ in Figure 3-2, would translate to the final wastewater bill that the
community would pay after the upgrade.
1
1.5
2
2.5
3
0.5 1 1.5 2 2.5Secondary ScoreCost Cap (Percent MHI)
Cost Cap versus Secondary Score
Cost Cap
Figure 3-2. Sliding scale for determining cost cap based on a community’s secondary score.
The horizontal axis represents percentages of a community’s median household income (MHI) that the community
would be expected to expend towards the pollution control project as a function of the secondary score shown on
the vertical axis.
3.1.3.1 The Remedy: Details, and an Example
The Department will consider the town's current treatment level (TN and TP) and current treatment
technology, which informs (along with the additional money amount) what the next level of treatment
should be. Once the amount of money available is determined, the Department and the applicant will
look at both capital and O&M investments that could be used to meet an individual variance, given what
money is available. Staff from the Department will review the application and the remedy. The staff will
generally include the Department’s economist, an engineer from the Technical and Financial Assistance
Bureau, staff from the Water Quality Standards Section, and staff from the Water Protection Bureau
(i.e., permitting).
The waste water treatment Plant (WWTP) applicant must propose a level of water treatment greater
than what they are currently meeting. If a community is already at the cost cap, then they still must look
at optimization options such as operator training and use all tools available within their cost cap which
could lead to water quality improvement. The variance must be established as close to the underlying
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numeric criteria (or general variance) as possible to show both that the highest attainable use is being
realized and that further incremental progress towards the underlying standard is occurring. The
Department and the applicant will evaluate options and select the alternative that would result in the
highest effluent condition that does not trigger substantial and widespread economic impacts. The
decision process should include engineering costs, design, treatment effectiveness, etc. The decision
regarding the pollution control project may also account for facility upgrades that do not directly
improve water quality. For example, if $4 million is available over 20 years for a given community, but $2
million is needed for replacing delivery system piping over that 20 years, it may be the case that only $2
million are available to directly reduce nutrient concentrations in the effluent.
For example, a community with 10,000 households has a MHI of $40,000/year. The community’s
secondary score is 1.5 and therefore the sliding scale indicates that 1.0% MHI needs to be expended on
the pollution control project. To receive the individual variance, the per-household wastewater bill for
the community would need to become, on average, $400 per year ($33.33 per month), because $400 is
1.0% of MHI in that community. If the average household in this community currently has a wastewater
bill that is $300 per year ($25.00 per month), then a bill increase of $100 per year per household on
average would be warranted to reach $400 per year or 1% MHI. Multiplying $100/year in an increased
wastewater bill by the number of households on the system (10,000) provides the total annual dollar
value available to be expended towards construction, operations, and maintenance of the wastewater
upgrade. In this hypothetical case, that amounts to $1 million (10,000 X $100) that could be spent per
year on an upgrade project. The upgrade itself may be significantly more than $1 million in initial capital
costs, but the annualized payback of capital costs plus O&M costs of the upgrade could not be more
than $1 million per year. Annualizing $1 million per year over several years could allow for a substantial
upgrade of several million dollars. Again, if the current wastewater bill of this town was already $400 or
higher, then no additional significant capital or O&M cost upgrade would be expected (i.e., no further
significant system upgrade would be required).
Finally, the final cost of the engineering project may not exactly match the dollar value associated with
the percent MHI determined via Figure 3-1 (i.e., the actual project cost could be somewhat lower or
somewhat higher than the dollar value equivalent for the percent MHI of the community in question).
Engineers should view the dollar value equivalent of the MHI derived from Figure 3-1 as a target, to help
select the most appropriate water pollution control solution for the community. In order to
accommodate actual engineering costs for the project, the Department will provide flexibility around
the dollar value arrived at via Figure 3-1, subject to final Department approval.
When the level of treatment required has been established and accepted by the Department, it will be
adopted by the Department following the Department’s formal rule making process and documented in
Circular DEQ-12B.
3.2 PRIVATE-SECTOR PERMITTEES
Individual nutrient standards variances (“individual variances”) may be granted to permit holders in the
private sector, on a case-by-case basis, because (1) the attainment of the base numeric nutrient
standards is precluded due to economic impacts, (2) treatment to the limits of technology still does not
enable the permittee to attain the base numeric nutrient standards, or (3) both reasons (§75-5-313 [2],
MCA). Individual variances may only be granted to a permittee after the permittee has made a
demonstration to the Department that adverse, significant economic impacts would occur, limits of
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technology have been reached, or both, and that there are no reasonable alternatives to discharging
into state waters.
Methods outlined below in Section 3.2.1 pertain to the economic-impact rationale (bullet 1 in the
paragraph above) and are almost identical to those presented in EPA (1995). If adverse substantial and
widespread economic impacts to a private entity trying to comply with nutrient standards are
demonstrated, the facility upgrade (cost cap) will be determined via approaches discussed in Section
3.2.3.
Permittees applying for an individual variance based on discharging at the limits of technology do not
have to prepare the economic analysis presented below in Section 3.2.1. Rather, they should
demonstrate to the Department that the waste treatment system they are proposing can achieve, at a
minimum, the nitrogen and phosphorus concentrations described in Section 1.2 of this document, and
that achieving those concentrations still does not enable them to attain the base numeric nutrient
standards at a seasonal 14Q5 flow. Various factors will have a bearing on the final effluent
concentrations approved by the Department for individual variances discussed in this paragraph.
3.2.1 Substantial and Widespread Economic Impacts: Process Overview
The following is an overview of the steps required to carry out a substantial and widespread economic
analysis for a private-sector permittee. The evaluation can be undertaken directly in an Excel
spreadsheet template which contains instructions. The template is called
“PrivateEntity_Worksheet_EPACostModel_2014.xlsx” and is available from the Department.
Step 1: Verify Project Costs and Calculate the Annual Cost of the Pollution control project to the
private entity.
Step 2: Substantial Test. Run a financial impact analysis on the private entity to assess the extent to
which existing or planned activities and/or employment will be reduced as a result of meeting the water
quality standards. The primary measure of whether substantial impact will occur to the private entity is
profitability. The secondary measures include indicators of liquidity, solvency, and leverage.
Step 3: Widespread Test. If impacts on the private entity are expected to be substantial, then the
applicant goes on to demonstrate whether they are also expected to be widespread to the defined
study area.
Note: Estimated changes in socio-economic indicators in a defined area as a result of the additional
pollution costs will be used to determine whether widespread impacts would occur.
Step 4: Final Determination of Substantial and Widespread Economic Impacts. If both substantial and
widespread impacts are demonstrated, then a permittee is eligible for an individual variance after
having demonstrated to the Department that they considered alternatives to discharging (including but
not limited to trading, land application, and permit compliance schedules). If widespread impacts have
not been demonstrated, then the permittee is not eligible for an individual variance (however, the
permittee may still receive a general variance if they can comply with the end-of-pipe treatment
requirements thereof).
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3.2.2 Completing the Substantial and Widespread Assessment Spreadsheet
Detailed steps for completing the substantial and widespread cost assessment are found in the
spreadsheet template “PrivateEntity_Worksheet_EPACostModel_2014.xlsx” (available from the
Department). Readers should refer to that spreadsheet, as it is self-explanatory and instructions are
found throughout. Detailed steps for private sector entities are also found in Chapter 3 of EPA (1995).
Below are a few additional details which may help clarify some of the steps:
1. Start at the far left tab of the spreadsheet (“Instructions [Steps to Take]”) and review the
instructions. They are the same steps outlined in Section 3.2.1 above. Proceed to subsequent
tabs to the right, making sure not to skip any of the worksheets.
2. Summarize the project on Worksheet A.
3. There are no worksheets B through F on the private test.
4. The next worksheet is G where one details the costs of the project.
5. In the next tab, carefully read the ‘Substantial Impact Instructions’.
6. In worksheets H through L, the four main substantial tests are presented. For these tests, profit
and solvency ratios are calculated with and without the additional compliance costs (taking into
consideration the entity's ability to increase its prices to cover part or all of the costs).
Comparing these ratios to each other and to industry benchmarks provides a measure of the
impact on the entity of additional wastewater costs. For profit and solvency, the main question
is how these will be affected by additional pollution control costs. The Liquidity and leverage
measures look at how a firm is doing right now financially, and how much additional financial
burden they could take on.
7. In the Tab entitled “Substan.Impacts_Determined”, instruction is given as to how to interpret
the results from the ‘Substantial’ tests in worksheets H through L.
8. If a ‘Substantial‘ finding is made, then proceed on to the next tab. If it is not made, then the
variance based on evaluations in this sub-section will not be given.
9. On the ‘DEQ Widespread Criteria’ tab, complete the descriptive questions. Then, complete the
primary questions and determine the outcome as to whether impacts are widespread. If still
unclear, complete the secondary questions and again evaluate.
10. In order to be eligible for an individual variance, both substantial and widespread tests must be
satisfied.
11. If both substantial and widespread impacts are demonstrated from additional pollution control
costs, see Section 3.2.3 below.
3.2.3 The Remedy: Determining the Cost of the Pollution Control Project for
Private Entities
U.S. Environmental Protection Agency (1995) provides very little guidance as to what financial
expenditure should be made towards water pollution control when a private firm has demonstrated
substantial and widespread impacts would occur if they complied with the standards. EPA (1995) only
states that “…if substantial and widespread economic and social impacts have been demonstrated, then
the discharger will not have to meet the water quality standards. The discharger will, however, be
expected to undertake some additional pollution control.”
In cases where substantial and widespread economic impact has been demonstrated per methods
outlined here in Section 3.2, the Department expects that in most cases the discharger (and their
engineers) will propose to the Department some level of effluent improvement beyond that which they
are currently doing, but less stringent that the general variances concentrations (which are in statute at
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§75-5-313, MCA through May 2016, but have been adopted as Department rules). A likely scenario
would be that the discharger could implement a treatment technology one level less sophisticated than
that required to meet the general variance concentrations. Basic definitions for different treatment
levels are found in Falk et al. (2011); for example, through 2016 the general variance requirement for
dischargers > 1 million gallons per day corresponds to treatment level 2 in Falk et al. (2011). When the
discharger and the Department have come to agreement on the level of treatment required, the
treatment levels will be adopted by the Department following the Department’s formal rule making
process, and documented in Circular DEQ-12B.
4.0 GUIDELINES FOR DEVELOPING INDIVIDUAL NUTRIENT STANDARDS
VARIANCES VIA WATER QUALITY MODELING, AND THE RELATION OF THESE
TO SITE-SPECIFIC NUMERIC NUTRIENT CRITERIA
Circumstances may arise where, for a specific discharger, it may not make sense to move to the new,
lower general variance concentrations at the time the Department updates them during a triennial
standards review. Similarly, it may not make sense for a discharger to upgrade to one of the nutrient
reduction steps (see Section 2.0 of this document) that have been defined for the 3 permit cycles
subsequent to the initial treatment requirements (e.g., 1 mg TP/L and 10 mg TN/L) defined in statute at
§75-5-313 (5)(b), MCA.
In some cases a permittee may be able to demonstrate, using water quality modeling and reach-specific
data, that greater emphasis on reducing one nutrient (the target nutrient) will achieve the same desired
water-quality conditions as can be achieved by equally emphasizing reduction of both nutrients.
Requiring a point source discharger to immediately install sophisticated nutrient-removal technologies
to reduce the non-target nutrient to levels more stringent than what is in statute at §75-5-313(5)(b),
MCA may not be the most prudent nutrient control expenditure, and would cause the discharger to
incur unnecessary economic expense. Since this can be interpreted as a form of economic impact, sensu
§75-5-313(1), MCA, these situations are appropriately addressed by individual variances.
If such a case can be demonstrated to the satisfaction of the Department, then a permittee can apply for
an individual variance which will include discharger-specific limits reflecting the highest attainable
condition for the receiving water rather than limits based on a general variance concentration. The
permittee will be required to provide monitoring water-quality data that can be used to determine if the
justification for less stringent effluent limits continues to hold true (i.e., status monitoring is required),
consistent with New Rule I(4). This is because status can change, for example due to substantive
nonpoint source cleanups upstream of the discharger.
The purpose of Section 4.0 is to provide guidelines for the types of information the Department would
need to evaluate in order to grant an individual variance that allows a discharger to (1) remain at
treatment levels less stringent than general variance requirements defined in statute at §75-5-313
(5)(b), MCA (or Department updates), or (2) remain at levels less stringent than the reduction steps in
Section 2.0 of this guidance document. The nutrient concentrations identified via this modeling may be
adopted as site-specific standards under the Board of Environmental Review’s rulemaking authority in
§75-5-301(2), MCA, but would require an analysis of their downstream effects prior to adoption
(downstream effects are discussed further in Section 4.2).
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4.1 MECHANISTIC AND EMPIRICAL MODELING APPROACHES FOR ESTABLISHING
REACH-SPECIFIC NUTRIENT STANDARDS AND INDIVIDUAL VARIANCES (IF
NECESSARY)
Two general modeling approaches may be used:
1. Simulations based on mechanistic computer models
2. Demonstration of use support based on empirical data
Whichever approach is selected—and in fact both approaches can be pursued simultaneously—the
Department would like a 2-year biological characterization of the reach in question. A solid
understanding of the biological status existing under the current level of water quality is required. Later
in this document (Section 6.0) a simplified empirical approach to site-specific nutrient criteria is
presented, and has a 3-year minimum data requirement. The empirical modeling approach in the
present section has only a 2-year requirement because the amount of data to be collected and
frequency of sampling is so much higher in this case.
Factors (both natural and human-caused) independent of nutrient concentrations can influence
biological integrity and need to be understood. The biological characterization will change from case to
case, but will normally involve collection of diatoms, macroinvertebrates, benthic and phytoplankton
algae density, and critical physical and chemical parameters that influence these. See Section A2.0 of
Appendix A for an example of the types and quantity of biological data and the rationale for each.
The following provides further detail on the two modeling approaches bulleted above.
Simulation Based on Mechanistic Computer Models. The Department will consider mechanistic model
results that demonstrate that the lowering of one nutrient (e.g., TP) without the lowering (or more
likely, with less lowering) of the other would achieve essentially the same water quality endpoint (i.e.,
similar water quality and biological goals), subject to Department approval of the model and the model’s
parameterization. Modeled endpoints may include changes in water quality (pH, dissolved oxygen, etc.),
and benthic and phytoplankton algae density. Mechanistic models should be supported by data from a
Department-approved study design that includes characterization of the chemical, biological, and
hydrological conditions of the study reach during a lower-than-average baseflow condition. Data
collection should follow Department SOPs.
The Department encourages the use of the QUAL2K model (Chapra et al., 2010) but may consider results
from other water quality models as well. Assuming the point source is a major contributor to the
nutrients in the receiving stream, modeled nutrient reduction scenarios from the facility can vary, but
scenarios based on the five treatment levels described in Falk et al. (2011)—which represent steps in
biological nutrient removal technologies—are encouraged by the Department. The Department will
consider nitrogen and phosphorus independently in this analysis.
The state of the art in computer water quality/algal growth modeling is such that nutrient co-limitation
and community interaction of river flora is poorly simulated (or is not simulated at all). Models usually
treat algal growth dynamics in streams and rivers as though the algae were a monoculture (which is not
the case). Because of the uncertainties in model simulations, the Department will require monitoring
(per New Rule I[4]) for dischargers that are permitted to depart from general variance concentration
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requirements via an individual variance based on a mechanistic model. The intent of the monitoring is to
corroborate (or refute) the computer simulated results. At a minimum, growing season benthic-algae
sampling will be required for a reach of the river downstream of the permittee’s mixing zone, to be
established in coordination with the Department. If the base numeric nutrient standard for the river in
question was developed based on another water quality endpoint (for example, pH), then data
collection should also include that parameter. If the collected data and the computer modeling results
corroborate one another, then a reach-specific base numeric nutrient standard may be in order.
However any reach-specific nutrient standards must be adopted by the Board of Environmental Review
under its rulemaking authority in §75-5-301(2), MCA, and would require an analysis of their downstream
effects prior to adoption.
Demonstration of Use Support Based on Empirical Data. Permittees may begin at any time to collect
nutrient concentration, benthic and phytoplankton algae, and other biological and water quality data in
the receiving waterbody downstream of their mixing zone. In cases where the Department’s base
numeric nutrient standards for the waterbody were developed using a specific water quality endpoint
(for example, pH), data collection must include that parameter. Data collection should follow
Department SOPs. Permittees are strongly encouraged to coordinate with the Department on study
design and data collection protocols upfront, to assure that the data types and quantity will be
acceptable to the Department when the time comes for evaluating the outcomes. For example, it has
been shown that chlorination of effluent can, in some cases, mute the effects of nutrients for some
distance downstream (Gammons et al., 2011); this would need to be accounted for in any study design.
Subject to Department approval, these data may be used to develop an individual variance. If the
collected data conclusively indicate that beneficial uses of the waterbody are fully supported, then
reach-specific base numeric nutrient standards may be appropriate. Any reach-specific nutrient
standards so determined may be adopted by the Board of Environmental Review under its rulemaking
authority in §75-5-301(2), MCA, but would require an analysis of their downstream effects prior to
adoption. An example of an empirical approach to developing reach-specific nutrient criteria is provided
in Section 2.0 of Appendix A.
4.2 PROTECTION OF DOWNSTREAM BENEFICIAL USES
In order to be adopted as standards, any reach-specific criteria developed for a receiving stream using a
mechanistic or empirical model will also need to protect downstream beneficial uses. This is a basic
requirement of a water quality standard under the Federal Clean Water Act. “How far downstream” is a
consideration which will vary from case-to-case; an example is provided in Sections 2.7 and 4.0 of
Appendix A. Mechanistic models have very clear advantages over empirical models for running
hypothetical scenarios and assessing potential downstream impacts, however a mechanistic model will
normally be more expensive to complete. A budget estimate for a mechanistic and an empirical model is
provided in Section 6.0 of Appendix A. If it results that modeling (of either type) has shown that
beneficial uses of the assessed reach can be protected with site-specific criteria, but a downstream
reach will be negatively impacted by the higher concentrations of one (or both) nutrients, then the
Department would require treatment levels which would support the uses in the downstream
waterbody, or it would have to recommend against the site-specific standards.
4.3. UNWARRANTED COST AND ECONOMIC IMPACT
In order to satisfy the economic impact component of an individual variance (§75-5-313(2), MCA) which
may be developed as a result of the modeling methods described above, permittees should provide the
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Department approximate estimates of the capital costs, and operations and maintenance costs, which
would have been expended in order to upgrade the facility to any new general variance concentrations.
The intent is to demonstrate that there were substantial savings in capital costs, materials, fuel, and
energy by opting not to upgrade the facility. The permittee can compare the cost saved to the MHI of
the community, similar to what is done for determining substantial and widespread economic impacts
(see steps 1 through 5, Section 3.1.1); however, the Department wants to make clear that no specific
percent of MHI needs to be realized in order for this aspect of the analysis to be satisfied. Permittees are
encouraged to work with the Department’s economist when carrying out this analysis (Jeff Blend or his
successor). Capital costs saved would not include design-related work and overhead. Operations and
maintenance cost saved should be estimates of fuel and/or electrical consumption, and other materials
(e.g., chemicals). Permittees are not required to carry out a complex analysis comparing the relative
economic or social value of protecting one resource (the stream or river) vs. another (e.g., air quality)
and then trying to quantify the relative savings. Rather, the Department wants a straight-forward
quantification of cost savings associated with the key factors of concern (capitol costs, fuel and electrical
consumption, and routine materials used such as chemical additions).
4.4 PERIODIC REVIEW OF THE INDIVIDUAL VARIANCE, BOARD ADOPTION OF SITE-
SPECIFIC CRITERIA
Status monitoring of the receiving stream and the affected downstream waterbody will be used to
evaluate the individual variance justification going forward. For example: model results have shown that
a large reduction of phosphorus by the permittee would render the receiving stream P-limited and in full
support of beneficial uses, without a major reduction in nitrogen. At the same time, nonpoint
contributions of nitrogen to the downstream part of the waterbody of concern are presently large
enough that a substantial reduction of nitrogen load at the permittee’s facility would have had little or
no beneficial effect on the waterbody’s uses. As a result, the permittee’s individual variance reflects a
low TP concentration and a TN concentration of, say, 9 mg/L. If in the next ten years (of the twenty year
variance period) nonpoint sources cleanup sufficiently that the facility’s 9 mg TN/L concentration has
become a sizeable proportion of the downstream nitrogen load and reduction of that load would benefit
the stream, then the justification for the 9 mg TN/L will have changed. Any updated individual variance
would reflect a lower TN concentration. As before, modeling could be used to help derive the updated
TN concentration.
The ultimate endpoint of the modeling work is likely to be site-specific nutrient standards for the
receiving stream, adopted by the Board. As indicated earlier, model-based site-specific criteria will need
to demonstrably protect downstream beneficial uses. In some cases where site-specific criteria have
been developed, an individual variance may still be necessary, as the site-specific criteria may not be
immediately achievable because (for example) the site-specific criteria are still below the limits of
technology and the point source is a major proportion of the stream flow. Individual variances approved
by the Department become effective and may be incorporated into a permit only after a public hearing
and adoption by the Department (§75-5-313(4), MCA).
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5.0 GUIDANCE PERTAINING TO ALTERNATIVE NUTRIENT STANDARDS
VARIANCES
Statute provides for alternative nutrient standards variances (“alternative variances”) in addition to
general and individual variances. A permittee may request an alternative variance if the permittee
demonstrates to the Department that achieving the nutrient concentrations established for an
individual or general nutrient standards variance would not result in a significant reduction of instream
nutrient loading (§75-5-313[10][a], MCA). The idea behind the alternative variance is that the permittee
is a very small proportion of the watershed’s nutrient load. For example the permittee’s discharge may
be extremely small compared to the volume of the waterbody, and/or the waterbody may be highly
dominated by non-point nutrient sources. Either way, an alternative variance is an option when the
permitee can demonstrate that meeting general variance concentrations at §75-5-313[5][b], MCA (or
future Department updates) would not result in an environmentally significant improvement in water
quality and material progress towards attainment and maintenance of the waterbody's base numeric
nutrient standards. Alternative variances are evaluated by the Department on case-by-case basis.
Permittees may apply for an alternative variance for nitrogen, phosphorus, or both.
In many circumstances the need for an alternative variance will be precluded because the non-
significance of the permittee’s nutrient load to the waterbody in question will have already been
accounted for in the development of the waterbody’s Total Maximum Daily Load (TMDL), consistent
with New Rule I(7). In such cases, the waste-load allocation in the TMDL becomes the basis for the
discharge permit and no variance of any kind is needed. Put differently, the concentration of nutrients in
the permittee’s discharge may be higher than the general variance concentrations in statute (or future
Department updates), but it would not be sensible— from a practical or economic perspective—to
require the permittee to reduce those concentrations because their contribution to the overall
watershed nutrient load is insignificant. Therefore, the permittee’s existing discharge concentrations
become the basis of the TMDL and the permit limit; no variance is needed.
In the absence of a completed TMDL, a permittee may apply for an alternative variance if it can be
reasonably demonstrated to the Department that the discharger’s nutrient load is non-significant.
Watershed models are useful for this purpose and Section 4.0 of this document addresses some
modeling techniques. The Department will consider other modeling approach as well. The alternative
variance derived via modeling can operate as an interim effluent limit until the time that the TMDL is
completed.
Whether a point source is or is not a significant load in a watershed is not likely to be a static situation,
and will probably change over time. Therefore, a permittee granted an alternative variance must
demonstrate throughout the variance period that the facility’s discharge has remained insignificant (per
§75-5-313[10][b], MCA). This is necessary because if, for example, nonpoint source cleanups were
substantial, the facility’s nutrient load may have become significant in the watershed over time and may
be preventing the waterbody from attaining the base numeric nutrient standards. Permittees granted an
alternative variance should work with the Department regarding the frequency of monitoring needed to
carry out the demonstration discussed in this paragraph.
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6.0 STREAMLINED METHODS FOR DEVELOPING SITE-SPECIFIC NUMERIC
NUTRIENT CRITERIA
6.1 BACKGROUND AND RATIONALE
Numeric nutrient criteria were developed for all major and several minor ecoregions in Montana (Suplee
and Watson, 2013). Suplee and Watson (2013) also include a limited number of site specific criteria, and
it has been acknowledged that the Department will need to develop other site-specific nutrient criteria
going forward. A criteria development approach using empirical or process-based models (e.g., QUAL2K)
is provided in Section 4.0 of this document. That process is, however, data intensive. There will likely be
streams which warrant site-specific numeric nutrient criteria but for which a smaller dataset and less
rigorous analysis can be used; this paper outlines a simplified, streamlined approach for doing this.
Criteria developed via this streamlined process may be adopted as site-specific standards under the
Board of Environmental Review’s rulemaking authority in §75-5-301(2), MCA.
This simplified approach was motivated by observations stemming from the application of the
Department’s methodology for assessing stream eutrophication (Suplee and Sada de Suplee, 2011).
Using those methods, some streams have been found to support a healthy stream ecology and are in
compliance with the biologically-based assessment parameters (e.g., levels of benthic chlorophyll a,
macroinvertebrate Hilsenhoff Biotic Index (HBI) metric), but show exceedences of one or both of the
nutrients (N, P) recommended as criteria. Site-specific numeric nutrient criteria are likely to be
appropriate in these situations.
Section 6.0 is organized as follows:
Section 6.2: The basic concept and approach is presented;
Section 6.3: Assessment of biological health and minimum dataset requirements are provided; and
Section 6.4: A case study example is given.
6.2 SITE-SPECIFIC METHODS
This section outlines the streamlined approach for deriving site-specific nutrient criteria for streams and
small rivers. The methods cover the situation where a stream has higher-than-expected nutrient
concentrations, but at the same time has full biological support. However, site-specific criteria could also
be developed for the reverse situation. That is, a stream which shows effects of elevated nutrients (e.g.,
excess algae) but which has nutrient concentrations at or below the standards. This could occur because
the type of phosphorus-bearing rock in the stream’s watershed weathers easily, and releases more
soluble inorganic P than what is typical for the ecoregion. The Department expects that latter situations
to be uncommon, and will address them on a case-by-case basis using the concepts outlined below (or
rather, the mirror image of them).
Figure 6-1 shows a flowchart of the process outlined in Section 5.0. Note that the figure only applies to
the situation where full biological health is observed in the stream, but the stream’s nutrient
concentrations are above the standards.
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Figure 6-1. Overview of the Streamlined Site-specific Criteria Methods.
The diagram applies to cases where nutrient concentrations are elevated above standards, but biological integrity
is demonstrated.
6.2.1 Two Site-specific Methods
Nutrient concentration data from reference sites have been compiled for each ecoregion (Suplee and
Watson, 2013). Data from dose-response studies (nutrient concentration as dose, impact to beneficial
use as response) applicable to each ecoregion have also been compiled in that document. Each of these
data types provide concentration ranges within which this streamlined site-specific criteria method can
operate. In applying this method, two scenarios will be encountered.
Scenario 1: Figure 6-2 illustrates how information from ecoregionally-applicable reference sites can be
used. It is assumed here that a stream assessment (per Suplee and Sada de Suplee, 2011) has already
been carried out and has shown that a particular stream’s biological condition supports all uses, i.e., no
detrimental eutrophication effects have been observed. In Figure 6-2, the Department’s recommended
criterion (black dot with X) falls within the reference distribution of the ecoregion’s reference-site data
(median dataset2)(Suplee and Watson, 2013). This occurs in a number of ecoregions, for example for TP
in the Middle Rockies, due to the fact that dose-response studies were the primary drivers in setting the
criteria. What the data show us is that there are reference sites which routinely manifest nutrient
concentrations higher than the regional criterion; therefore, there is a range of concentrations beyond
the recommended nutrient criterion that may still be protective within the ecoregion.
In scenario 1, If an assessed stream meets the Department’s biological expectations and manifests a
nutrient concentration falling between the ecoregion nutrient standard (Montana Department of
2 The median dataset must be used for this analysis and is available from the Department. In the median dataset,
within any given ecoregion, nutrient concentrations from each reference site were first reduced to a median, and
then descriptive statistics were calculated for the population of site medians. For an example, see Table 3-1B in
Suplee and Watson (2013).
Assemble minimum
biological and
nutrient-
concentration
dataset for the
stream
Do the stream’s
concentrations of
nitrogen or
phosphorus exceed
the standards?
NO YES
Does the dataset
indicate full
biological health?
NO YES
Compare stream’s
nutrient concs. to (1)
reference distribution,
or (2) range from dose-
response studies, in
Suplee and Watson
(2013).
Does stream meet
conditions for site-
specific criteria?
NO YES
Site-specific
nutrient
criteria using
streamlined
process are
appropriate
END END END
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Environmental Quality, 2014a) and the 95th percentile of the ecoregion’s reference dataset (within the
dashed arrow, Figure 6-2), then the assessed stream is eligible for a site-specific criterion. The stream’s
new criterion should be established at the 80th percentile of the stream’s nutrient dataset3. This
criterion can then be recommended to the Board of Environmental Review for adoption as a site-specific
nutrient standard during a subsequent triennial review.
Figure 6-2. Scenario 1. Candidate site-specific nutrient criteria may fall between the ecoregional
nutrient standard (black dot with X) and the 95th percentile of the applicable reference distribution
(dashed arrow).
The reference distribution used must be the median dataset from Suplee and Watson (2013), or its equivalent
update. This method only applies to streams that demonstrate good biological health and full support of beneficial
uses using assessment methods in Suplee and Sada de Suplee (2011).
Scenario 2: In other cases, the criteria recommended by the Department are very near to or beyond the
95th percentile of the ecoregional reference distribution. In these cases, the approach shown in Figure 6-
2 will not work and an alternative approach is illustrated in Figure 6-3. For each level III ecoregion,
Suplee and Watson (2013) have provided in each concluding paragraph a range of concentrations from
the dose-response studies they reviewed. The dose-response studies most applicable to the ecoregion in
question (not the broader range of generally-applicable studies) will provide the concentration range
within which site-specific criteria can be identified. Contact the Department’s Water Quality Standards
Section if you are unsure which concentrations range applies.
3 Assuming the assessment methodology in Suplee and Sada de Suplee (2011) remains the same, the stream in
question would, in the future, be assessed using the binomial test for streams considered compliant with the
nutrient criteria (i.e., null hypothesis is “stream compliant with nutrient criteria”). Due to the allowable
exceedence rate (20%) and the gray zone (15%) established in the binomial test, a site-specific nutrient criterion
set at the 80th percentile of the site’s existing dataset will always PASS the binomial in the future (assuming the
stream’s nutrient conditions are unchanged). The T-test would also be PASS.
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Figure 6-3. Scenario 2. Site-specific criteria derivation method for cases where a Department-
recommended criterion is near or above the 95th percentile of the ecoregional reference distribution.
Candidate site-specific nutrient criteria fall between the criterion recommended by the Department (black dot
with X) and the upper range of the values from the dose-response studies specifically applicable to the ecoregion
in question (dashed arrow with gray fringe). The dose-response studies must be from Suplee and Watson (2013),
or equivalent updates.
If an assessed stream meets the Department’s biological expectations but manifests a nutrient
concentration above the Department’s criterion, and that criterion is near or above the 95th percentile
of the ecoregional reference dataset, then the range of concentrations from the applicable dose-
response studies should be reviewed. If the assessed stream’s nutrient concentration at the 80th
percentile falls within the range of the regionally-applicable dose-response studies, then that
concentration can be used as a site-specific criterion. This criterion can then be recommended to the
Board of Environmental Review to be adopted as a site-specific nutrient standard.
6.2.2 Other Methods
Recent work in the scientific literature provides a means to develop site-specific criteria on a stream-by-
stream basis; the method was specifically developed for western regions of the United States (Olson and
Hawkins, 2013). This method uses a geospatially-driven model that considers major environmental
factors within a watershed that influence nutrient concentrations in streams (geology, precipitation, soil
bulk density, etc.). It should be pointed out that the method is not for use in the plains region of
Montana (Olson and Hawkins, 2013).
The Department may consider results provided by others that have used the Olson and Hawkins (2013)
method. (Again, this is predicated on the assumption that full biological support is shown in the stream.)
However, results from this model will need to be reviewed by the Department on a case-by-case basis. If
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approved, they can be recommended to the Board of Environmental Review for adoption as site-specific
standards.
In general, streams whose nutrient concentrations fall outside of the defined ranges in Figures 6-2 and
6-3 are not eligible for this streamlined approach. Rather, methods outlined in Section 4.0 of this
document should be used. There may also be cases where an upstream level IV ecoregion with naturally
high nutrient concentrations is influencing the stream in question, and the reach-specific methods in
Section 4.0 of Suplee and Watson (2013) may be applicable.
6.3 CONFIRMATION OF BIOLOGICAL HEALTH, AND MINIMUM DATASET
This section addresses the minimum requirements needed to assert that the biological health of the
stream fully supports beneficial uses.
6.3.1 Assessment of the Biological Health of the Stream
Assessment methods outlined in Suplee and Sada de Suplee (2011) or updates will be used. That
assessment methodology is designed to provide a minimum dataset by which eutrophication-based
impacts to beneficial stream uses can be assessed. There are different methods and data requirements
for different parts of the state (western MT, and the plains region of eastern MT). Data types include:
1. A minimum nutrient dataset (usually 12-13 independent samples)
2. Benthic chlorophyll a samples
3. Periphyton samples for taxonomic identification and biological metrics
4. Aquatic insect (macroinvertebrate) samples for taxonomic identification and biological metrics
Data (chemical and biological) are to be collected during the defined growing season for the ecoregion
in question, which corresponds with the period of application of the nutrient standards (see Circular
DEQ-12A, Montana Department of Environmental Quality, 2014a). Although Suplee and Sada de Suplee
(2011) define specific biological metrics, etc. to be considered, other chemical and biological data or
metrics may also be included when the entire suite of stream-specific data is evaluated.
For example, in a western MT stream it has been found that an assessed stream’s nutrient
concentrations are elevated and fail both statistical tests (Suplee and Sada de Suplee, 2011); the
binomial, which looks as the proportion of observations above the criterion, and the t-test, which
addresses the dataset average and the presence of high outliers. However the biological signals are all
acceptable; benthic algal biomass is below the 120 mg Chla/m2 (reach average), diatom metrics (where
applicable) show a low probability of nutrient impairment (<51%), and the macroinvertebrate-based HBI
metric is acceptable since it is < 4, meaning water quality is very good (Hilsenhoff, 1987). This stream
would be a candidate for site-specific nutrient.
6.3.2 Dataset Minimum
All data collection must follow Department SOPs (e.g., Montana Department of Environmental Quality,
2011b; Montana Department of Environmental Quality, 2011a; MT Department of Environmental
Quality, 2012; Suplee and Sada de Suplee, 2011). For the purposes of developing site-specific nutrient
criteria via this process, the dataset needs to have been collected for three years (though not necessarily
contiguously) for all of the data types required in Suplee and Sada de Suplee (2011). For western
Montana streams, this would be 13 nutrient samples, ≥ 3 sampling events for benthic chlorophyll a, ≥ 3
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samples for diatoms (where applicable), and ≥ 3 samples for macroinvertebrates. If the dataset
minimums to complete a stream assessment were achieved after just two years of data collection
(which is common), a complete third year of data must be collected as well. For prairie streams, data
types should include 13 nutrient samples, measurement of dissolved oxygen (5 continuous days at a
minimum, during summer), ≥ 3 diatom diatoms, and visual assessment of aquatic plant densities during
each field visit (Montana Department of Environmental Quality, 2011b), for a minimum of three years.
The complete, three-year dataset is taken through the assessment data matrix. In some cases the
additional year may change the initial outcome, and it may result that site-specific criteria are not
warranted. However if the assessed stream again arrives to a scenario like the example in Section 6.3.1
above, , site-specific nutrient criteria are likely warranted and the approaches outlined in Section 6.2
may be applied.
6.3.3 Consideration of the Other Nutrient
Where a site-specific criterion is warranted for a nutrient elevated above the ecoregion- based
standards, consideration must be given to the other nutrient in the stream (N vs. P, and vise-versa). For
example, a stream manifesting good biological health but elevated P concentrations may very likely be N
limited, and should be maintained so. If N limitation were alleviated, there is a high likelihood that the
biological health of the stream would be impacted. The Redfield ratio (Redfield, 1958) will be used as a
general guide for establishing which nutrient limits (by-mass ratio < 6, N limits; by-mass ratio > 10, P
limits) and for establishing the final concentration of the other nutrient.
What the updated criterion for the non-elevated nutrient should be needs to be determined on a case-
by-case basis in conjunction with the Department. A first-cut approximation would be roughly 75% of
the established ecoregional criterion concentration.
In some cases, both N and P will be elevated above the ecoregional nutrient standards in Circular DEQ-
12A (Montana Department of Environmental Quality, 2014a). In such cases each nutrient should be
evaluated per these methods and it may result that site-specific criteria for both N and P will be higher
than the nutrient standards. In such cases factors other than nutrients (e.g., heavy riparian shading) are
likely limiting nutrient effects in the stream and potential downstream effects of a standards change
should be given consideration.
6.4 CASE-STUDY EXAMPLE
The following is a case which lends itself to site-specific nutrient criteria.
6.4.1 Data Summary for Stream X (in Middle Rockies Ecoregion)
Years of data: 3 (2004, 2011, 2012)
Number of Nutrient Samples: 12-14 (meets minimum)
Average Total Phosphorus (TP) Concentration: 35 µg/L
Average Total Nitrogen (TN) Concentration: 40 µg/L
Benthic Chlorophyll a Samples: 3 (each comprised of 11 sub-replicates) (meets minimum)
Diatom Metric Samples: Not applicable (Department has no validated diatom-based metrics for the
Middle Rockies ecoregion at this time)
Macroinvertebrates Samples: 3 (meets minimum)
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6.4.2 The Assessment of Stream X
The applicable criteria for the Middle Rockies are 30 µg TP/L and 300 µg TN/L (Circular DEQ-12A,
Montana Department of Environmental Quality, 2014a). Data for stream X were evaluated and TN was
found to be quite low (average = 40 µg/L), well below the recommended ecoregional criterion of 300
µg/L. However TP averaged 35 µg/L and was above the ecoregional criterion of 30 µg/L. All biological
indicators were found to be acceptable In additional, other aspects of the data were considered. The
macroinvertebrate O/E scores were reviewed to see if they were above 1.04 (none were). The benthic
chlorophyll a concentrations were not only below the threshold (120 mg Chla/m2) they were very low
(<< 50 mg Chla/m2), as was algal ash free dry mass (AFDM). Nitrate concentrations were also evaluated,
and all concentrations were very low.
6.4.3 Site-specific Criteria Derivation for Stream X using the Streamlined
Approach
The Middle Rockies ecoregion standard (where stream X is located) is 30 µg TP/L; this value matches the
82nd percentile of the Middle Rockies’ reference data (median dataset; Suplee and Watson, 2013). The
TP concentration at the 80th percentile of stream X’s dataset is 42 µg TP/L, a concentration equal to the
89th percentile in the Middle Rockies reference dataset. Therefore, stream X fits scenario 1 (Figure 6-2)
because its site-specific TP value (42 µg/L) falls between the Department’s recommended criterion and
the 95th percentile of the Middle Rockies reference dataset. Stream X’s new criterion (42 µg TP/L) is not
too far above the Department’s criterion, so a large reduction in the stream’s TN criterion is not
warranted. But it is prudent to set the TN lower than 300, to 250 µg TN/L (which is at the 97th percentile
of the Middle Rockies reference distribution). This maintains a Redfield ratio of < 6 which should help
maintain N limitation. The site specific criteria would be 42 µg TP/L and 250 µg TN/L, applicable during
the growing season for the Middle Rockies (July1-Sept 30).
4 O/E scores decline from an ideal score of 1.0 due to impacts from a variety of stressors (excess sediment, heavy
metals, elevated temperatures, etc.). However it is not uncommon to see scores > 1.0. These indicate the stream
has more species of macroinvertebrates than the model is expecting to see for the region. Essentially, slightly
elevated nutrient levels have led to a less austere environment and more species can exist than is normally seen.
For this reason O/E scores > 1.0 can be indicative of nutrient enrichment above reference. When nutrient
enrichment becomes excessive, O/E scores again drop below 1 due to species loss.
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APPENDIX A: RECOMMENDATIONS FOR SAMPLING AND MODELING THE
EAST GALLATIN RIVER TO ACCOMPLISH MULTIPLE OBJECTIVES
A1.0 BACKGROUND
The Department indicated in its draft numeric nutrient standards rule package that a person may collect
and analyze water quality and biological data along a reach of stream or river to determine if reach-
specific numeric nutrient criteria different from those of the Department are warranted. A draft
proposal of this type was provided to the Department in July 2012 for the East Gallatin River (HDR
Engineering, Inc., 2012)5. The Sampling and Analysis Plan (SAP) provided to the Department in July 2012
(HDR Engineering, Inc., 2012) is based on sites that were sampled in 2009-2010 for the purpose of
determining flow-stage relationships in the East Gallatin River. Building on those sites, the following are
recommendations for an optimized study design which can be used to develop reach-specific nitrogen
and phosphorus criteria for the East Gallatin River. It is hoped that this document may also serve as a
blueprint for similar work that may be carried out on other Montana rivers or streams.
The Department already has a public-reviewed and finalized assessment methodology for determining
when a stream reach is impaired by excess nitrogen and phosphorus (Suplee and Sada de Suplee, 2011).
However, that assessment methodology was designed to be a minimum data method and was not
intended to be sufficient for deriving reach-specific criteria. Therefore, the reader will find that methods
recommended below are more data intensive than those needed to complete an assessment via the
assessment methodology.
A1.1 DESIGN AND POSSIBLE OUTCOMES OF THE INVESTIGATION
The East Gallatin River is an excellent case study in which to explore several variations on the
development of reach-specific criteria. These variations include:
1. The case where a stream reach may have natural factors (e.g. high turbidity, cold temperature,
etc.) that suppress benthic algae growth, and therefore reach-specific criteria are appropriate;
2. The case where benthic algae is found to be above nuisance levels, but modeling shows the
algae problem can be addressed by focusing on the reduction of one nutrient more than the
other; or
3. The case where reach-specific numeric nutrient criteria for a reach of the East Gallatin River are
appropriate, but consideration of downstream beneficial uses precludes their application.
Figure A1-1 below forms the basis for the recommendations in the rest of this document.
5 It should be noted that the Department has developed reach-specific criteria for the East Gallatin River using
approaches somewhat different than those provided here. See Section 4.0 in Suplee and Watson (2012).
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Figure A1-1. Flowchart outlining various outcomes from the analysis of reach-specific data and the
development of reach-specific criteria.
1. Based on the analysis of data collected along the East
Gallatin River between the Bridger and Hyalite creek
confluences, from July to September, is benthic algae
density above or below benchmarks?
BELOW ABOVE
6. Done. Study and/or
modeling does not indicate
reach specific criteria are
appropriate. TP and TN
criteria developed by the
Department in 2012 should
be retained for reach
8. River ecological status complex.
Consultation between the Department
and city need to determine course of
action/how much additional work
should be done. Further/different
sampling may be required.
2. Do other biological and/or other water
quality indicators along the reach exceed
standards or benchmarks?
YES NO
5. Develop reach-specific criteria. Will downstream
beneficial uses be protected by the criteria?
NO YES
3. Does modeling show that benthic algae benchmarks
can be met in the reach by reducing one nutrient
substantially more than the other (e.g., reduce end-of
pipe TP to 0.1 mg/L, but only reduce TN to 8 mg/L)?
NO YES
4. Will downstream beneficial uses be
protected, especially in regards to the
nutrient which is not being substantially
reduced?
NO YES
7. Reach Specific
Criteria Appropriate.
Develop reach-
specific criteria and
monitor biological
status of the receiving
stream
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Figure A1-1 provides for an empirical approach to developing reach-specific criteria and assessing
downstream effects of these criteria. It provides a mechanistic model approach (starting in Box 3), as
well as an approach where either option can be pursued (starting in Box 5). Regardless of which
approach is taken, as shown in Figure A1-1, proper biological characterization of the mainstem East
Gallatin River needs to be undertaken. Both criteria derivation approaches require robust field data and
an understanding of the impairment status of the river in relation to nuisance algae and/or other
aquatic life.
Please note that “other water quality indicators” (Box 2) in Figure A1-1 does not include a comparison of
measured nutrient concentrations to currently recommended criteria for the reach. (That would be
circular.) It does, however, include things such as pH, Dissolved Oxygen (DO), and DO delta; i.e., effect
variables. It is a foregone conclusion (based on existing data) that much or all of the reach below the
Bozeman water reclamation facility (WRF) outfall will manifest nutrient concentrations in excess of the
Department’s recommended criteria.
Figure A1-1 does not provide closure in all circumstances. There is a pathway by which one can arrive to
Box 8 “River ecological status complex”. If the study findings lead to this outcome, it is not clear at this
point what the path forward would be. It may require substantially more sampling and analysis. The
assumption here is that the Department and the city would want to discuss what (if any) further work
would be carried out, and what the endpoints might look like.
A1.2 SUMMARY OF THE BASIC APPROACHES TO REACH-SPECIFIC CRITERIA
Two broadly defined modeling approaches to developing criteria (empirical and mechanistic) are
detailed in the following sections. Briefly, the basic characteristics and strengths and weaknesses of each
are given below.
Empirical Approach. Fewer overall sites to sample compared to mechanistic modeling and, as a result,
lower overall cost. Samples can be collected most years during baseflow. Samples need to be collected
for at least three years, however two of those three years are already needed for the basic biological
characterization of the reach and the same sites can be used for both. Robustness of the empirical
statistical relationships are difficult to know in advance and could require additional data beyond three
years. The ability to run “what if” scenarios or extrapolate predictions outside of the range of data from
which the relationship is developed is much more limited compared to that of the mechanistic model.
Mechanistic Approach. This method requires more overall sites and more complex data collection
compared to the empirical approach, with concomitantly higher cost. The mechanistic model still
requires a two-year biological characterization, only some sites of which will overlap with the sampling
sites for the model. The model will also require collection of DO, pH, etc. with deployed water-quality
sondes. As you can imagine, these factors increase the cost and complexity of this approach. Data for
calibration and validation of the model can be collected during one field season, provided that both
collections are done near to peak growth and approximately a month apart. Two separate low-flow
years of data is probably a better corroboration of the model. Preferably, data collection should occur
during a low baseflow (i.e., near the seasonal 14Q5 or, optionally, when baseflow is below the long-term
seasonal average). This ensures that physical and biogeochemical conditions are consistent with that of
the targeted low-flow period. Once the model is corroborated (i.e., validated) it can readily be used to
run “what if” scenarios which can assess downstream uses, different nutrient reduction strategies at the
Bozeman WRF and their effects, etc.
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A2.0 BIOLOGICAL CHARACTERIZATION OF THE EAST GALLATIN RIVER, AND
THE EMPIRICAL MODEL APPROACH TO DERIVING REACH-SPECIFIC CRITERIA
Objective 1: Determine the current biological condition of the reach of the East Gallatin River between
the Bridger Creek and West Gallatin River confluences during the growing season (summer and early
fall) and compare the results to standards and benchmarks used to assess stream eutrophication.
A2.1 DETAILED CONSIDERATION OF THE OBJECTIVE 1
The following questions are designed to address objective 1 given above:
In the wadeable regions of the East Gallatin River between the Bridger Creek and West Gallatin River
confluences, during the July 20 to September 30 period, what:
(a) are the average benthic algae densities (quantified as chlorophyll a and ash free dry mass, per m2)?
(b) is the areal coverage and thickness of benthic algae and macrophytes (based on standardized visual
assessment methods)?
(c) is the range and central tendency of specified macroinvertebrate metric scores (MT Hilsenhoff Biotic
Index, O/E, and ephemeroptera, plecoptera, and trichoptera (EPT) taxa richness)?
(d) is the range and central tendency of specified diatom metric scores (WEMAP MVI and WEMAP WA
TN)?
(e) are the dissolved oxygen concentrations and pH compared to state standards, and what is the
dissolved oxygen delta (daily maximum minus the daily minimum)?
(f) are the concentrations of nitrogen and phosphorus (total and soluble) and total suspended solids?
(g) is the stream temperature, and incoming light intensity( in photosynthetically active radiation (PAR)
units, e.g., µmol quanta/m2∙s)?
(h) are the concentrations of herbicides which are frequently used in the watershed?
Note in the question at the start of Section A2.1 the dates during which data collection should occur
(July 20 to the end of September). These dates were based on the Middle Rockies growing season
(Suplee et al., 2007), and the fact that in the East Gallatin River the first three weeks of July have
considerably higher flows compared to August and September (shown in dark gray, Table A2-1).
Commencing July sampling after July 20th will generally exclude the higher flows and lead to data
collection during base flow conditions more consistent with August and September. Sampling could
extend into the first two weeks of October, if temperatures remain moderate and base flow conditions
remain reasonably stable (Suplee and Sada de Suplee, 2011).
Table A2-1. Discharge, ft3/sec for USGS Station 06048700 "East Gallatin River at Bozeman, Mont.".
Mean of daily values for 10 years of record (calculation period 2001-10-01 to 2011-09-30).
Day of
month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
1 42 47 45 118 283 433 164 52 43 40 55 47
2 44 43 44 128 267 441 155 51 42 41 55 47
3 44 42 46 124 268 453 147 53 39 42 57 47
4 41 43 48 112 297 433 142 53 37 44 56 47
5 43 44 47 121 295 418 141 51 39 48 55 47
6 43 47 46 148 328 425 130 52 42 50 53 47
7 41 44 46 139 364 479 124 51 43 51 55 46
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Table A2-1. Discharge, ft3/sec for USGS Station 06048700 "East Gallatin River at Bozeman, Mont.".
Mean of daily values for 10 years of record (calculation period 2001-10-01 to 2011-09-30).
Day of
month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
8 46 44 52 140 379 461 118 52 41 51 62 43
9 44 42 54 149 376 440 108 54 43 52 60 43
10 42 42 56 157 380 443 102 52 50 52 56 44
11 41 42 58 155 373 513 101 49 45 52 56 46
12 42 42 70 164 373 501 97 46 41 53 56 46
13 43 42 88 182 377 465 94 45 42 52 57 45
14 44 42 88 218 404 436 90 45 42 52 56 45
15 43 41 80 232 439 420 84 47 43 55 52 45
16 42 41 80 212 442 404 81 44 42 59 55 43
17 44 41 81 229 464 390 78 44 44 61 54 42
18 46 41 86 239 484 359 75 47 45 59 53 41
19 51 42 89 235 509 335 73 46 44 59 53 43
20 48 40 88 231 528 310 68 42 44 66 52 44
21 47 41 93 254 523 299 66 41 46 63 49 45
22 44 41 94 279 505 277 66 41 47 58 47 44
23 44 41 94 324 495 264 67 45 48 56 48 46
24 44 41 90 315 500 247 62 43 49 56 46 44
25 43 41 89 290 615 237 63 41 46 57 48 45
26 43 42 95 293 540 228 64 41 43 55 50 46
27 47 43 93 270 502 209 63 39 42 55 48 44
28 46 43 95 266 475 195 61 39 42 55 47 44
29 44 41 91 274 490 183 55 41 42 57 46 46
30 45 97 295 466 175 51 41 44 57 47 44
31 43 104 444 50 43 56 43
To further address the questions posed at the start of Section A2.1, it will be necessary to measure a
number of physico-chemical parameters; the rationale for measuring each of these is described below.
Biological parameters specified in the questions above were selected because they are known to be
directly influenced by or significantly correlate with lotic nutrient concentrations. The Department has
established benchmarks for most of the physic-chemical and biological variables, and East Gallatin River
data can be compared against these (Montana Department of Environmental Quality, 2012a; Suplee and
Sada de Suplee, 2011).
Benthic algae densities (chlorophyll a [Chla] and ash free dry mass [AFDM] per m2). Based on work in
the Clark Fork River, statewide public opinion surveys, and a whole-stream dose-response study, the
Department is using average Chla levels of 125 to 150 mg/m2 and 35 g AFDM/m2 as harm-to-use
thresholds for western Montana rivers and streams (Dodds et al., 1997; Suplee et al., 2009; Suplee and
Sada de Suplee, 2011). Algae densities above these levels impact the recreation and aquatic life uses.
The Department also has standard visual assessment methods to asses algal and macrophyte density at
a coarser scale (Montana Department of Environmental Quality, 2011b). The general composition,
amount, color, and condition of aquatic plants are visually assessed in the field using the Aquatic Plant
Visual Assessment Form. This information helps describe the health and productivity of the aquatic
ecosystem, records nuisance aquatic plant problems, documents changes in the plant community over
time, and can be used to help corroborate the quantitative Chla results.
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Macroinvertebrate metrics. The Hilsenhoff Biotic Index (HBI) is included as part of the Department’s
current eutrophication assessment methodology (see Suplee and Sada de Suplee, 2011). The HBI index
was designed to assess biological impacts caused by organic enrichment and eutrophication (Hilsenhoff,
1987). The Department considers HBI scores in the Middle Rockies > 4.0 to indicate an impact to aquatic
life (Suplee and Sada de Suplee, 2011). Two other metrics, O/E and EPT richness, were considered during
the development of the eutrophication assessment methodology since both metrics correlated
significantly to nutrient concentrations (Tetra Tech, Inc., 2010); however, for simplicity, only the HBI was
retained in that methodology. Nevertheless, it would be of value to include these metrics in this study.
The O/E metric evaluates the taxa diversity that was actually Observed compared to an Expected taxa
diversity for the location where the sample was collected. The Department uses an O/E ratio of 1.0 to
0.9 as un-impacted; ≤ 0.9 is the harm threshold (i.e., loss of 10% of species). Modest stream nutrient
enrichment can actually cause the metric to be > 1.0. A Bray-Curtis Index should be calculated to
accompany the O/E to help interpret counterintuitive O/E scores (MT Department of Environmental
Quality, 2012). The EPT richness metric was part of older DEQ protocols and has application to
intermountain valley and foothill streams. EPT richness values > 14 are considered healthy and this value
will decline with water quality impacts (Bukantis, 1998).
Diatom metrics. The Department currently addresses nutrient impacts using increaser diatom taxa
metrics which were developed using discriminant function analysis (Bahls et al., 2008; Teply, 2010b;
Teply, 2010a; Suplee and Sada de Suplee, 2011). Currently there is no calibrated and validated model for
the ecoregion in which the East Gallatin River resides (the Department hopes to have such a metric in a
year or so). Therefore, two diatom metrics are recommended (one for TN, one for TP) which were
developed by others and which correlate closely with stream nutrient concentrations in Montana (Teply,
2010a). The metrics are WEMAP WA TN (for TN) and WMAP MVI (for TP); each was developed from
work in the Western Environmental Monitoring and Assessment Program (EMAP) of the early 2000s.
Results that differ largely from the regression line shown in Tetra Tech (2010) might suggest a stream
with characteristics different from the Middle Rockies norm; for example, a WEMAP MVI diatom score
of 1.5 associated with a TP concentration of 0.25 mg/L would be well outside the expected pattern (one
would expect a score closer to 3)(Tetra Tech, Inc., 2010).
Dissolved oxygen, pH. Standards for dissolved oxygen (DO) and pH for a B-1 waterbody are established
in state law (Montana Department of Environmental Quality, 2012a). DO and pH have been linked to
elevated nutrient concentrations (Stevenson et al., 2012), making them good parameters to measure.
But the Department has frequently observed that DO minima are not found to be out of compliance in
heavily eutrophied streams, at least during summer, due to stream re-aeration. However, punctuated
DO problems can occur in fall when the built-up algae senesce en masse (Suplee and Sada de Suplee,
2011). Therefore, in addition to state-adopted DO standards, the Department uses DO delta (daily
maximum minus the daily minimum) of 5.3 as a benchmark for excessive plant productivity and
respiration in streams (see Appendix C.2, Suplee and Sada de Suplee, 2011). Others have found DO delta
to be valuable in assessing eutrophication in northern rivers, and recommend a benchmark of 5.0
(Heiskary et al., 2010).
Concentration of nitrogen and phosphorus (total and soluble), total suspended solids, temperature,
incoming light intensity, and herbicide concentrations. These water quality parameters are critical for
the development of empirical relationships between algae density and nutrient concentrations.
Variables that influence light levels are particularly important for algal growth rates. Light
measurements can include PAR near the stream bottom, or (as a possible surrogate) measurements of
canopy density above the water’s surface. Temperature alters the growth rates of stream algae. In
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addition, stream samples for herbicides which have historically been used in the basin should be
collected as these, if present in sufficient concentration, could suppress algal growth. Previous work has
shown herbicides to be present in Montana rivers and streams, with atrazine, metolachlor, and triallate
being among the most commonly detected (Miller et al., 2005). Algae (as well as macrophytes) are
sensitive to these herbicides and growth can be suppressed at fairly low concentrations (see work by the
USGS and EPA at:
http://www.epa.gov/oppefed1/ecorisk_ders/aquatic_life_benchmark.htm#benchmarks, and
http://www.cerc.usgs.gov/clearinghouse/data/usgs_brd_cerc_d_cerc008.html . The Department would
not consider suppression of algal growth in the East Gallatin River due to herbicides as a viable rationale
for reach-specific nutrient criteria because (a) it is not a naturally occurring environmental variable and
(b) future application of BMPs might reduce the amount of herbicides reaching the river and this change
could remove the algae-suppressing effect.
A2.2 DATA COLLECTION METHODS
The Department has Standard Operating Procedures (SOPs) for the collection of benthic and
phytoplankton algae (both quantitative and qualitative methods)(Montana Department of
Environmental Quality, 2011b), diatoms (Montana Department of Environmental Quality, 2011a),
macroinvertebrates (MT Department of Environmental Quality, 2012), and water quality (Montana
Department of Environmental Quality, 2012b), and recommended methods for measuring DO, pH, and
DO delta when assessing eutrophication (Suplee and Sada de Suplee, 2011). The Department’s 3rd
iteration of the Field Procedures Manual (Montana Department of Environmental Quality, 2012b) also
summarizes parts of the SOPs most pertinent to field sampling. I recommend these methods be adhered
to for all sampling in the East Gallatin River. These documents can be found at:
http://deq.mt.gov/wqinfo/qaprogram/sops.mcpx.
A common trait of all the biological sampling methods is the necessity of laying out a short sampling
reach, which the Department usually refers to as a ‘site’. These short reaches are typically 150 to 300 m
in length in wadeable streams, and are delineated at the time of sampling as 40X the wetted width of
the stream or a minimum of 150 m. Sample collection at locations where there is a large proportion of
the river that is unwadeable requires special consideration and these situations are also addressed in
the SOPs.
Collection of DO, temperature, pH, and DO delta are best measured with deployed data sondes (e.g., YSI
6600s). Continuous collection of data via sondes is not needed at all stations but 1 or 2 along the East
Gallatin River study reach is recommended for biological characterization. These instruments can be
rented seasonally from commercial suppliers.
Details on data collection will need to be elaborated upon in the final Sampling and Analysis Plan (SAP)
developed to implement this general study design.
A2.3 RECOMMENDED SAMPLING SITES ALONG THE EAST GALLATIN RIVER
To address objective 1 and its associated questions, ten sampling sites have been identified along the
East Gallatin River between the Bridger Creek and West Gallatin River confluences (Figure A2-1). These
ten sites are key to the implementation of the empirical approach outlined in Section A1.2. Seven sites
(A to G; Figure A2-2) are intended for more intense chemical and biological sampling, while three (H to
J) may be less intensively sampled and are the foundation of the downstream use assessment.
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Site A (~0.7 miles downstream of the Bridger Creek confluence, at 45.71516, -111.0358): Establishes
water quality and biological conditions near the head of the study reach. Suplee and Watson (Suplee et
al., 2012) indicate that the East Gallatin River upstream of the Bridger Creek confluence should have a
higher TP criterion (to account for the natural influence of the Absaroka-Gallatin Volcanic Mountains
ecoregion). However, the elevated TP has been diluted out once Bridger Creek joins the river, and the
recommended criteria are then the same as for the Middle Rockies as a whole. The site is the natural
starting point for the work. This site also corresponds to site 1 of the mechanistic model (i.e., the
QUAL2K model).
Site B (~0.3 stream miles upstream of Bozeman WRF outfall, at 45.72568, -111.06469): Provides a
second site to characterize the upper extent of the study reach. It is also not far upstream from the
major point source on the river and so can provide a nearby point of reference for any changes
occurring downstream of the facility. See also, Figure 2-3.
Site C (~0.9 stream mile downstream of the Bozeman WRF outfall, at 45.7284, -111.072): First site
downstream of the city of Bozeman WRF discharge. A study shows that the facility’s effluent is
completely mixed within about 400 ft (0.08 miles) of the discharge (Cleasby and Dodge, 1999), although
flows at the time of the study were nearly double that of average conditions and nearly 3X the 7Q10.
This site—located about 0.9 miles downstream of the discharge— should capture changes in the river
due to the effluent, post-mixing. See also, Figure 2-3.
Site D (~0.3 stream miles downstream of the Riverside Water & Sewer District ponds, at 45.7363, -
111.07105): Conversations with Department staff indicate that the Riverside Water & Sewer District
ponds are a likely source of nutrients to the East Gallatin River. By establishing this site (and the one
upstream, site C) it should be possible to discern differences in river biology and water quality due to the
Bozeman WWTP effluent vs. any subsequent changes due to the ponds. See also, Figure 2-3. This site
also corresponds to QUAL2K model site 2.
Site E (~0.6 stream miles downstream of the Buster Gulch irrigation diversion, at 45.74765, -
111.08195): Site is established below a major water withdrawal to Buster Gulch. The site is established
in order to determine if lower water volume is having a measureable effect on water quality or biology
of the reach below the withdrawal.
Site F (Lower third of reach at 45.76698, -111.0968): Site will provide data representative of the reach
between site E upstream and site G downstream. There are few notable characteristics in this reach of
the river (e.g., point sources, tributaries, etc.) and this site will help ascertain the degree to which
upstream loads extend their influence downstream.
Site G (upstream of confluence with Hyalite Creek, at 45.7888, -111.1195 [same as site EGRF2]):
Establishes water quality and biological conditions near the end of the reach prior to the Hyalite Creek
confluence. This site corresponds to a site established in an earlier study on the river (PBS&J, 2010). Any
earlier data can be compared to that collected for this study. This site also corresponds to QUAL2K
model site 3.
Site H (just upstream of the Dry Creek Irrigation withdrawal, at 45.83059, -111.14617): Nutrient
criteria recommended for Hyalite Creek are higher for TP (due to natural geologic sources) and slightly
lower for TN (to maintain N limitation) than the reach of the East Gallatin River into which Hyalite flows
(Suplee et al., 2012). As such, Hyalite Creek is an important water quality change point. This site is
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intended to discern changes resulting from Hyalite Creek and to characterize the East Gallatin just prior
to the Dry Creek irrigation withdrawal. This location is the first site intended for the assessment of
downstream uses. This site also corresponds to QUAL2K model site 4.
Site I (just upstream of the Dry Creek Irrigation System return flow, at 45.88921, -111.26408): The Dry
Creek Irrigation system is one of, if not the largest, irrigation withdrawals on the East Gallatin River.
Irrigation return flows can be a significant source of nutrients and turbidity. The intent of this site is to
characterize the East Gallatin River just prior to the addition of irrigation return flow to the river. The
site is part of the assessment of downstream uses, and also corresponds to QUAL2K model site 5.
Site J (just upstream of the confluence with the West Gallatin River, at 45.8923, -111.3286 [same as
site EGRF1]): This site is located just upstream of the confluence with the West Gallatin River, and
should reflect effects from the Dry Creek irrigation return. The site corresponds to an earlier study site
(EGRF1; PBS&J, 2010) and so flow-stage relationships established there can be used; it also is the end of
the study reach. The site is part of the assessment of downstream uses, and also corresponds to QUAL2K
model site 6.
If resources are a constraint, objective 1 can be addressed with a scaled-down version of this plan. At
a very minimum, the Department recommends that sites B, C (or as alternate to C, D), F, G, H, I and J
be sampled.
A2.4 SAMPLING FREQUENCY AND DURATION OF STUDY
Each site should be sampled synoptically at least once during the months of July, August, and
September. This will provide good characterization of the sites during baseflow. Two years of data
should be collected for the basic biological characterization. This will provide enough information to
have some confidence in the biological status of the river during baseflow. If it is intended that the
empirical criteria-derivation approach is taken, at least one more year (three total) of baseflow data
should be collected at the sites. (Requirements associated with the mechanistic model approach are
addressed in Section A3.0.) However, if a particular year has unusual high flows ≥ 165% of the long-term
average August and September flows, data should not be collected until flows have declined to below
this volume. At the USGS gage station at Bozeman on the East Gallatin River (gage No. 06048700), the
long-term average flow in August and September is 45 ft3/sec; thus, until summer and fall flows fall
below 74 ft3/sec, sampling should not occur.
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Figure A2-1. Ten biological and water quality sampling sites along the East Gallatin River.
Sites A to G are for biological characterization of the East Gallatin River in the reach below the WRF. Sites H to J are for biological characterization and for
assessing downstream use protection.
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Figure A2-2. Sampling sites A to G along the East Gallatin River between the Bridger and Hyalite creek confluences.
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Figure A2-3. Close-up of the three sampling sites around the city of Bozeman WRF discharge. Green dot is USGS gage 06048700.
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A2.5 DATA ANALYSIS AND INTERPRETATION
Due to the number of variables measured (e.g. benthic algae density, macroinvertebrates, diatoms),
many different data combinations and outcomes are possible. The Department does not believe that
establishing a rigid analysis structure upfront—that is, laying out the exact statistical tests, data
aggregation methods, etc.—would be beneficial at this point. There are still a number of unknowns
going forward and we must allow ourselves some flexibility in how the data will be interpreted. When
statistical tests are, ultimately, carried out, a balance should be sought between type I and II error rates,
as has been instituted in other Department stream-assessment procedures (Suplee and Sada de Suplee,
2011). This will seek a balance between error that imposes unneeded cost on the regulated community,
and error that leads to degradation of (or lack of improvement to) the river environment (Mapstone,
1995).
A2.6 REACH SPECIFIC CRITERIA—EMPIRICAL APPROACH
If it appears that natural environmental factors are keeping benthic algae density below nuisance levels
in spite of elevated nutrient concentrations, then it may be possible to develop a reach-specific multiple
regression equation involving nitrogen, phosphorus, and the additional environmental variable(s) of
relevance, as has been done by others (e.g., Dodds et al., 1997; Biggs, 2000). Whether there will be
enough data to develop significant relationships is hard to predict in advance, especially if the reduced-
sites approach is selected; but it is safe to say the dataset will be relatively small and will require the
assumption that all (or most) sites are independent from one another and samples collected a month
apart are temporally independent. The Department has been able to substantiate similar assumptions in
other cases (see Appendix A.3, Suplee and Sada de Suplee, 2011).
The multiple regression might take on the following form (Neter et al., 1989):
Y = βo + β1X1 + β2X2 + β3X3 + βnXn
where Y is the dependent (or response) variable, what is being predicted or explained; βo is a constant
or Y-intercept; β1 is the slope (beta coefficient) for X1; X1 is the first independent variable that is
explaining the variance in Y; β2 is the slope for X2; X2 is the second independent variable that is
explaining the variance in Y; β3 is the slope for X3 and X3 is the third independent variable that is
explaining the variance in Y, and on so on for the total number of slope∙variables used (βnXn). For
purposes of this work, Y equals benthic algae density (mg Chla/m2, g AFDM/m2). Likely explanatory
variables (βs) would be Total Nitrogen (TN) concentration, Total Phosphorus (TP) concentrations, Total
Suspended Solids (TSS) concentration, and stream-bottom PAR. This same approach could be used to
explain relationships between other response and causal variables (e.g., macroinvertebrate HBI score as
the response [Y], TN, TP, and TSS as causal variables [βs]).
A2.7 PROTECTION OF DOWNSTREAM USES
The next step in the process is to determine if downstream uses will be protected by the reach-specific
criteria (Box 5, Figure A1-1). Nutrients are assimilated longitudinally in streams and elevated
concentrations will eventually decline due to biological uptake and adsorption to the sediments. Thus,
assessing protection of downstream uses amounts to an evaluation of whether or not the higher
nutrient concentrations being allowed upstream will have a deleterious effect downstream.
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It is unlikely that any reach-specific criteria in the East Gallatin River would affect the Missouri River. The
confluence of the three forks of the Missouri River results in orders-of-magnitude greater summer flows
than the East Gallatin River. For example, mean August flow in the Missouri River ~24 miles downstream
of the three forks is around 2,747 ft3/sec, whereas in the Gallatin River at Logan it is 490 ft3/sec, and
near the mouth of the East Gallatin River it is about 250 ft3/sec (Berkas et al., 2003; PBS&J, 2010). The
most likely impacts from reach-specific nutrient criteria would be in the reach of the East Gallatin River
downstream of the Hyalite Creek confluence. The nitrogen criterion recommended for the East Gallatin
River between Hyalite Creek and the confluence with the West Gallatin River is 290 µg TN/L, lower than
the 300 µg TN/L for the Middle Rockies (Suplee et al., 2012). Data suggest that the stream is nitrogen
limited (since TP is naturally elevated) and is the reason why a lower TN criterion has been
recommended there. A relaxation of the nitrogen criterion upstream of Hyalite Creek could very well
lead to use impacts if the nitrogen limitation is, consequently, alleviated. Two approaches (which tie to
Box 5 in Figure A1-1) can be taken to address downstream effects:
An empirical approach. If the sites along the East Gallatin River downstream from Hyalite Creek (sites H,
I, and J) show a general immunity to elevated nutrients (and the reach upstream of Hyalite Creek does
as well) due to some natural factor like elevated turbidity, then reach specific criteria in the East Gallatin
River could be extended all the way from the Bridger Creek confluence to the confluence with the West
Gallatin River, or even beyond, to the confluence with the Missouri River. However if the reach of the
East Gallatin River downstream of the Hyalite Creek confluence shows biological impacts/nuisance algae
above targets, then reach specific criteria that may be appropriate for the East Gallatin River further
upstream will not protect downstream uses, and should not be put in place.
A mechanistic modeling approach using QUAL2K. This approach links to Section 3.0. The model would
extend the full length of the East Gallatin River, between the Bridger Creek and West Gallatin River
confluences to ascertain whether nutrients at a certain concentration, moving downstream from the
point where Hyalite Creek confluences with the East Gallatin, would impact the beneficial uses further
downstream. Beneficial uses addressed by the model include DO delta, pH delta, and benthic algae
density. Please note that the mechanistic model requires additional types of sampling and sampling
sites (tributaries, irrigation withdrawals and returns) than the empirical approach; see Section A3.0.
The next section discusses approaches that can be used to develop a mechanistic model.
A3.0 DEVELOPING REACH SPECIFIC CRITERIA VIA THE MECHANISTIC
MODELING APPROACH
Objective: Collect enough data along the East Gallatin River between the Bridger Creek confluence and
the West Gallatin River confluence during a low-flow condition to be able to calibrate and confirm a
mechanistic QUAL2K model of the study reach.
This objective still requires adequate biological characterization of the reach, as outlined in Sections
A2.1 through A2.5. Many sites described in Section A2.0 overlap with model sites described below; this
was done in order to optimize sampling. To assure the reach is long enough to be able to judge the
validity of the rate coefficients used in the model, the longitudinal distance must be sufficient to observe
during calibration the decline in soluble nutrients, conversions to organic from algal death and recycling,
etc. It is the Department’s judgment that the East Gallatin River can be effectively modeled if the reach
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from above the Bozeman WRF to the West Gallatin River confluence (Figure A3-1) is considered, a
distance of approximately 25 stream miles.
Mechanistic models for criteria derivation require a robust set of field observations including streamflow
and water-quality data, measurements from continuously deployed sondes (including, at a minimum,
dissolved oxygen, pH, temperature, conductivity, and turbidity), and biogeochemical kinetic
observations (if possible). The Department has a detailed Quality Assurance Project Plan (Suplee et al.,
2006) and a technical report (Suplee and Sada de Suplee, 2011) on the use of the QUAL2K model for
developing reach-specific nutrient criteria; the reader is referred to those documents for greater detail.
Selected sites are best sampled during one low-flow summer and fall (i.e., a year with flows near the
seasonal 14Q5 of the East Gallatin River (McCarthy et al., 2004) or, alternatively, sequential low-flow
summers during the peak of the growing period. Consecutive years with base flows that are below
average is preferred but may not always be possible. If, during the initial biological and water-quality
characterization (Sections A2.1 through A2.5), it is found that herbicides are high enough to suppress
algal growth, the model will be severely compromised. Therefore, herbicide data are best collected
and then assessed in advance of the decision to complete the mechanistic model detailed below.
A3.1 SITES REQUIRING WATER QUALITY SONDE DEPLOYMENT
For the QUAL2K model, six sites are recommended (Figure 3-1). Sondes could be deployed continuously,
or for a week to ten days in middle to late August and then again for another week to ten days in middle
to late September, during period of relatively stable flow (or in two sequential Augusts if each has lower-
than-average baseflow).
Water quality samples for key model drivers (nutrient concentrations—which include total nitrogen,
nitrate+nitrite, ammonia, total phosphorus, and soluble reactive phosphorus; TSS and inorganic
suspended sediment (ISS); alkalinity; hardness; Carbonaceous Biochemical Oxygen Demand, run for 20
consecutive days(CBOD20); Total Organic Carbon [TOC]; and benthic and phytoplankton algae) need to
be collected at the six sites, at least once in August and once in September (or in sequential low flow
years). These data collections could potentially be synchronized with the data collection in Section A2.1.
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Figure A3-1. Map showing the six main sites along the East Gallatin River needed for the development of the QUAL2K model.
Twelve other sampling sites (tributaries, irrigation canal withdrawals, etc.) are needed to develop the model but are not shown on this map.
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The sites are:
Model Site 1 (~0.7 miles downstream of the Bridger Creek confluence, at 45.71516, -111.0358; same
as Site A): Establishes water quality boundary conditions near the upper-most point of interest on the
East Gallatin River based on reasons provided previously (page 9).
Model Site 2 (~0.3 stream miles downstream of the Riverside Water & Sewer District ponds, at
45.7363, -111.07105; same as Site D): For the purposes of the model, this site is intended to represent
conditions in the East Gallatin River after the full mixing of Bozeman’s WRF effluent discharge and any
effects that may be coming from the Riverside Water & Sewer District ponds (see Figure A2-3).
Model Site 3 (upstream of confluence with Hyalite Creek, at 45.7888, -111.1195 [same as site G and
site EGRF2]): Establishes water quality conditions in the East Gallatin River just before the confluence of
Hyalite Creek, which naturally has differing nutrient concentrations (Suplee et al., 2012). This site
corresponds to a site established in an earlier study (PBS&J, 2010). Any earlier data and flow-stage
relationships can be compared to that collected for this study.
Model Site 4 (just upstream of the Dry Creek Irrigation withdrawal, at 45.83059, -111.14617, same as
site H): Nutrient criteria recommended for Hyalite Creek are higher for TP (due to natural geologic
sources) and slightly lower for TN (to maintain N limitation) than the reach of the East Gallatin River into
which Hyalite flows (Suplee et al., 2012). As such, Hyalite Creek is an important water quality change
point. Model Site 4 is intended to discern changes resulting from Hyalite Creek, and characterize the
East Gallatin just prior to the Dry Creek irrigation withdrawal.
Model Site5 (just upstream of the Dry Creek Irrigation System return flow, at 45.88921, -111.26408,
same as site I): The Dry Creek Irrigation system is one of if not the largest irrigation withdrawals on the
East Gallatin River. Irrigation return flows can be a significant source of nutrients and turbidity. The
intent of this site is to characterize the East Gallatin River just prior to the addition of irrigation return
flow to the river. Changes in water quality as a result of this inflow will be captured by the next site
downstream, model site 6.
Model Site 6 (just upstream of the confluence with the West Gallatin River, at 45.8923, -111.3286
[same as site J and site EGRF1]): This site is located just upstream of the confluence with the West
Gallatin River, and should reflect any effects from the Dry Creek irrigation return. The site corresponds
to an earlier study site (EGRF1; PBS&J, 2010) and flow-stage relationships established there can be used;
it also is the end of the modeled reach.
A3.2 ADDITIONAL SITES REQUIRING FLOW AND WATER QUALITY DATA
Proper quantification of the water balance, associated mass fluxes, and water quality changes resulting
from inputs and outputs to the East Gallatin River are key to a successful modeling strategy. As a result,
there are a number of large and small tributaries inflows, irrigation withdrawals and return flows, and
point source contributions that need to be quantified. These should be sampled for concentrations of
nutrients (total nitrogen, nitrate+nitrite, ammonia, total phosphorus, and soluble reactive phosphorus),
TOC, alkalinity, TSS and ISS, hardness, and CBOD20 along with instantaneous measurement of
temperature, DO, conductivity, pH, and flow.
A list of important hydrologic features that the Department believes should be characterized is shown
below. Other tributaries and canals may be included if greater model detail is desired:
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1. Bozeman WRF effluent
2. Withdrawal to Buster Gulch irrigation diversion, located ~0.6 upstream of Site E (see Figure 2-1);
flow only
3. Mouth of Hyalite Creek
4. Withdrawal to Dry Creek irrigation diversion, just downstream of model site 4 (flow only)
5. Mouth of Smith Creek
6. Mouth of Dry Creek
7. Mouth of Ben Hart Creek
8. Mouth of Story Creek
9. Mouth of Cowen Creek
10 Mouth of Gibson Creek
10. Return flow from Dry Creek irrigation diversion (just downstream of model site 5)
11. Mouth of Thompson Creek
12. Mouth of Bull Run Creek
It should be noted that prior to the field assessment, diurnal variation of the discharge of the
wastewater from the Bozeman WRF should be considered. If flows from the WRF are significantly
variable such that they alter the diurnal flow characteristics of the East Gallatin River itself, further
discussions with the Department should be commenced about using a time-variable flow model
necessary to represent these changes and their associated effect on water quality.
A3.3 OTHER DATA
In addition to the boundary conditions identified previously, forcing functions of air temperature,
dewpoint, windspeed, and cloud cover are required to develop incoming photosynthetically active
radiation (PAR) estimates and associated heat balances with QUAL2K. The Department has not taken the
time to investigate whether suitable information is available from Gallatin Field (or other stations), but it
is recommended that such information be assessed to determine availability as well as whether it is
appropriate for the East Gallatin River corridor. If suitable information is not available, it is
recommended that a meteorological station be placed nearby to measure these inputs for the model.
A3.4 NUMERIC NUTRIENT CRITERIA DERIVATION PROCESS VIA QUAL2K
A properly calibrated and validated QUAL2K model is necessary for nutrient criteria derivation. Basic
criteria for determining when the model is calibrated and validated can be found in Suplee et al. (2006)
and are further elaborated upon in Flynn and Suplee (Flynn and Suplee, 2013). Numeric nutrient criteria
can be ascertained by simulating incremental nutrient additions, or more likely in this case nutrient
reductions, to the point where water quality standards (e.g., DO, pH), benchmarks (benthic algae
density), or other ecological indicators are in compliance /achieved. Detailed discussions of this process
are found in Section 13 of Flynn and Suplee (Flynn and Suplee, 2013).
A4.0 CAN BENEFICIAL USES BE SUPPORTED BY APPLYING GREATER
EMPHASIS ON REDUCING ONE NUTRIENT?
The model described in Section A3.0 can be used to answer certain questions regardless of whether or
not the East Gallatin River is found to have nuisance algae levels or other undesirable water quality
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characteristics. If it is established that algae density is above benchmarks, the model can be used to
explore “what if” scenarios, including “what if the city of Bozeman greatly reduced its TP load to the East
Gallatin but only reduced its TN load somewhat?”
Figure A4-1 helps illustrates the concept. Taken from Flynn and Suplee (Flynn and Suplee, 2013), Figure
A4-1 shows growth limitation factors (0-1 scaling factor) from nitrogen, phosphorus, or light at any given
point along the river. The horizontal line nearest to the X-axis is the most-limiting factor.
Figure A4-1. QUAL2K model results for nitrogen, phosphorus, and light limitation of benthic algae in
the Yellowstone River. From Flynn and Suplee (2013).
What can be ascertained from Figure A4-1 is that in the case of point-source inputs, the nutrient
limitation term can greatly change. In this example, nitrogen limitation is strong downstream of the city
of Billings for some distance due to phosphorus load additions from the Billings WWTP (note: the
nitrogen load is also large, but the phosphorus load evidently has a much stronger effect because it
leads to river phosphorus concentrations far above saturation levels for benthic algae). But the nitrogen-
limitation status then changes due to external conditions. So within a model, questions can be posed
such as: (1) “What if the Billings TP load were to be greatly reduced such that phosphorus could be
made limiting (or co-limiting) with nitrogen?”, (2) “What effect would this have on benthic algae levels
0.0
0.2
0.4
0.6
0.8
1.0
0.00100.00200.00300.00400.00500.00600.00 Growth Limitation Factor (dimensionless)River Station (km)
Nitrogen Limitation
Phosphorus Limitation
Light Limitation
Miles CityTerryGlendiveForsythBillingsSidneyHuntley DamCartersville DamIntake DamWaco-Custer DamYellowstone DamRancher's DamBighorn RiverCusterPowder RiverFlow direction
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in the immediate vicinity of the wastewater discharge?”, and (3) “What would be the effect further
downstream?”.
In the case the East Gallatin River, such an exercise would greatly help us understand if a greater
reduction in WRF phosphorus (the less expensive nutrient to eliminate) would achieve benthic algae
targets by pushing the East Gallatin to P limitation. The model could also be used to see the downstream
effects. We know that Hyalite Creek introduces naturally-elevated TP concentrations; in all probability,
any TP limitation achieved further upstream would there be lost. The model could also show how
changes to WRF treatment systems affect benthic algae. Model results may possibly indicate that a
substantial reduction in TN from the WRF is necessary so that nitrogen limitation (and beneficial uses)
can be maintained below the Hyalite Creek confluence. Again, the main point is that with the QUAL2K
model “what if” scenarios can be evaluated.
A5.0 STATUS MONITORING
If reach specific criteria are developed and it appears that downstream uses will be protected, and those
criteria are moving towards adoption by the Board of Environmental Review, the last step in the process
is status monitoring. The state-of-the-art in both mechanistic and empirical models is such that they
inherently have noise, and confirmation of use-support of the reach-specific criteria is needed to assure
stream protection. It is recommended that model sites 1 through 6 be used for this purpose regardless
of the method used (mechanistic model or empirical model) to develop the criteria. Data collection
should focus on the endpoints of concern (benthic algae density, macroinverebrate metrics, diatom
metrics), and (if QUAL2K modeling was used) other endpoints (like pH) that were used in developing the
criteria. Presuming that the criteria can be met by changes to the WRF alone, then, after upgrades
occur, five years continuous monitoring is recommended at a minimum, to be carried out by the city or
its consultants. Five years will also allow enough time to apply robust non-parametric trend statistics to
the dataset (Helsel and Hirsch, 2002). Models developed via the methods outlined in Sections A2.6 and
A3.0 may show that, due to nonpoint source contributions, an upgrade to the WRF cannot in and of
itself achieve the reach-specific criteria. In this case, the Department and the city should discuss how to
proceed with status monitoring. TMDLs for nonpoint source cleanups or application of BMPs generally
recognize that implementation will take years (5+), and this should play an important role in
determining the monitoring status timeline.
A6.0 BUDGET ESTIMATES
An estimate was made for the cost to complete the data collection and analysis for each of the three
major aspects discussed: (1) the biological characterization, followed by either (2) empirical statistical
modeling or (3) QUAL2K modeling. Estimates shown are total, that is, the grand total to complete each
task including development, calibration, and validation of the models, and any criteria developed
thereof. Status monitoring, which would occur afterwards, is not included. Cost estimates were based
on 2012 analytical laboratory price sheets, costs for purchasing small equipment or rental of large
equipment, etc. They should be viewed as estimates only, as best professional judgment was needed to
estimate hours of labor for field data collection, professional data analysis and modeling, etc. See
Appendix A1 for details.
1. Biological characterization: $75,220
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The following are additional costs to be added to that above in order to complete the task:
A. Empirical Model Approach: $30,900
B. QUAL2K Model Approach: $113,635
If the empirical approach is taken, the grand total (biological characterization plus the empirical
statistical model) is $106,120. If the minimized study (sites B, D, F, G, H, I and J only) is selected for the
empirical approach, which again includes the biological characterization, the grand total drops to
$75,853. If the mechanistic model approach using QUAL2K is taken, the grand total (biological
characterization plus the calibrated and validated model) is $188,855. If the minimized study (sites B, D,
F, G, H, I and J only) is selected for the biological characterization, the grand total for the QUAL2K model
approach drops to $168,500.
A7.0 NEXT STEPS
This document has outlined the basic conceptual framework for (a) characterizing the biological and
water-quality status of the East Gallatin River (Section A2.0), (b) using empirical methods to derive the
criteria (Sections A2.6), (c) using mechanistic modeling approaches to derive the criteria (Section 3.0),
(d) consideration of downstream effects (Sections A2.7 and Section A4.0), and (e) biological status
monitoring (Section A5.0). This document provides several pathways and options to study and model
the East Gallatin River.
If work outlined in this document is to be undertaken, the next logical step would be to develop a
detailed SAP. Potentially, a Quality Assurance Project Plan (QAPP) may need to be developed, but that
document may be optional so long as Department SOPs are closely adhered to and the SAP provides
sufficient detail on topics that are not specifically covered in DEQ SOPs. Further discussion with the
Departments Quality Control Officer (Mindy McCarthy; MMcCarthy3@mt.gov ) should clarify if a QAPP
is needed to further support field sampling. If reach-specific criteria are found to be needed and the
QUAL2K model is going to be used, it would be worth further consultation with the Department on a
QAPP specific to the model as well as discussions with Department staff during model development.
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APPENDIX A1
Table A1-1. Biological Characterization (2-year study, up to three months per summer). This work is undertaken regardless of preferred modeling approach.
SITE Benthic Algae (Chla) Benthic Algae (AFDM) Macroinvertebrates Diatoms Water Quality (nutrients, TSS)* Herbicides**
Frequency Cost/ sample Frequency Cost/ sample Frequency Cost/ sample Frequency Cost/ sample Frequency Cost/ sample Frequency Cost/ sample
A 6 $1,170 6 $300 4 $980 2 $500 6 $960.00 5 $750
B 6 $1,170 6 $300 4 $980 2 $500 6 $960.00 5 $750
C 6 $1,170 6 $300 4 $980 2 $500 6 $960.00 5 $750
D 6 $1,170 6 $300 4 $980 2 $500 6 $960.00 5 $750
E 6 $1,170 6 $300 4 $980 2 $500 6 $960.00 5 $750
F 6 $1,170 6 $300 4 $980 2 $500 6 $960.00 5 $750
G 6 $1,170 6 $300 4 $980 2 $500 6 $960.00 5 $750
H 6 $1,170 6 $300 2 $490 1 $250 6 $960.00 5 $750
I 6 $1,170 6 $300 2 $490 1 $250 6 $960.00 5 $750
J 6 $1,170 6 $300 2 $490 1 $250 6 $960.00 5 $750
Totals: $11,700 $3,000 $8,330 $4,250 $9,600 $7,500
Subtotals, analytical costs: $44,380
YSI 6600 Sonde Rental: $2,240 Assume 2 sondes, deployed for 1 week each summer for two summers ($560 X 2 X 2). * TSS $20.00
Purchase YSI 85 $1,350 For instantaneous DO, temperature, and conductivity. Separate low-cost pH meter can be purchased. TN $40.00
Labor in field: $14,250 Assume a field team of 2 people, 10 sites, 3 hrs/site, average of 4.75 trips per site (for both years), assume $50/hr. TP $30.00
Data analysis $10,000 Assume 1 person, contracted, professional environmental consulting firm SRP $30.00
Misc. supplies: $3,000 macroinvertebrate nets, filters, filter apperatus, vehicle gasoline, etc. nitrate + nitrite $25.00
GRAND TOTAL, Biological Characterization: $75,220 total ammonia $15.00
Analytical (min sites) Field labor (min sites) GRAND TOTAL, min. sites (B, C, F, G, H, I, J): $54,865 $160.00
$28,300 $9,975
**N, P, and S containing pesticides (Method E507 modified). SRP = Soluble Reactive Phosphate, AFDM = Algal Ash Free Dry Mass
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Table A1-2. Statistical Empirical Model (One additional year of data in additional to the biological characterization).
SITE Benthic Algae (Chla) Benthic Algae (AFDM) Macroinvertebrates Diatoms Water Quality (nutrients, TSS)* Herbicides
Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample
A 3 $585 3 $150 2 $490 1 $250 3 $480.00 2 $300
B 3 $585 3 $150 2 $490 1 $250 3 $480.00 2 $300
C 3 $585 3 $150 2 $490 1 $250 3 $480.00 2 $300
D 3 $585 3 $150 2 $490 1 $250 3 $480.00 2 $300
E 3 $585 3 $150 2 $490 1 $250 3 $480.00 2 $300
F 3 $585 3 $150 2 $490 1 $250 3 $480.00 2 $300
G 3 $585 3 $150 2 $490 1 $250 3 $480.00 2 $300
H 3 $585 3 $150 2 $490 1 $250 3 $480.00 2 $300
I 3 $585 3 $150 2 $490 1 $250 3 $480.00 2 $300
J 3 $585 3 $150 2 $490 1 $250 3 $480.00 2 $300
Totals: $5,850 $1,500 $4,900 $2,500 $4,800 $3,000
Subtotals, analytical costs: $22,550
YSI 6600 Sonde Rental: $560 Assume 1sondes, deployed for 1 week for 1 summers ($560 X 1 X 1).
Labor in field: $6,990 Assume a field team of 2 people, 10 sites, 3 hrs/site, average of 2.333 trips per site, assume $50/hr.
Data analysi:s $15,000 Assume 1 person, contracted, professional environmental consulting firm. This would be final report and emperical model development
Misc. supplies: $800 macroinvertebrate nets, filters, filter apperatus, vehicle gasoline, etc.
Year 3 Total: $30,900
Emperical Model, TOTAL‡: $106,120 Analytical (min sites) Field labor (min sites) Year 3 Total, min. sites (B, C, F, G H, I, J): $20,988 $14,735 $4,893
Emperical Model, TOTAL, min sites (B, C, F, G, H, I, J)‡: $75,853
‡Cost includes what was spent for bio characterization in first two years.
TSS = Total Suspended Solids, AFDM = Algal Ash Free Dry Mass
Table A1-3a. QUAL2K Model main sites (data in addition to data from the biological characterization). Assumes a single year sampling in Aug and Sept.
SITE Benthic Algae (Chla) Benthic Algae (AFDM) Phytoplankton Chla Nutrients* TSS, ISS, Alk, Hardness, TOC† CBOD20
Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample
1 (same as A) 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
2 (same as D) 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
3 (same as G) 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
4 (same as H) 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
5 (same as I) 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
6 (same as J) 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
Totals: $2,340 $600 $780 $1,260 $720 $720
*TN $40.00 †TSS $20
TP $30.00 ISS $20
SRP $30.00 alkalinity $10
nitrate + nitrite $25.00 hardness $20
total ammonia $15.00 TOC $35
total nutrients: $140.00 total WQ: $105.00
ISS = inorganic suspended sediment, TSS = Total Suspended Solids, SRP = Soluble Reactive Phosphate, Alk = Alkalinity, TOC = Total Organic Carbon, AFDM = Algal Ash Free Dry Mass
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Table A1-3b. QUAL2K Model, Additional Sites. Assumes a single year sampling in Aug and Sept.
Additional Sites Benthic Algae (Chla) Benthic Algae (AFDM) Phytoplankton Chla Nutrients* TSS, ISS, Alk, Hardness, TOC† CBOD20
Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample Frequency Cost/sample
(two flow sites)
Bozeman WRF 0 $0 0 $0 0 $0 3 $420.00 3 $315 3 $180
Hyalite Cr mouth 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
Smith Cr mouth 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
Dry Creek mouth 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
Ben Hart Cr mouth 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
Story Cr mouth 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
Cowen Cr mouth 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
Gibson Cr moutn 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
Dry Creek Irrig. return 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
Thompson Cr mouth 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
Bull Run Cr mouth 2 $390 2 $100 2 $130 2 $280.00 2 $210 2 $120
Totals: $3,900 $1,000 $1,300 $3,220 $2,415 $1,380
Subtotals, analytical costs: $19,635
YSI 6600 Sonde Rental: $10,800 Assume 6 sondes, deployed for 2 weeks in Aug and 2 weeks in Sept ($1800/month X 6).
Labor in field: $12,000 Assume a field team of 2 people, 16 sites, 3 hrs/site, average of 2.5 trips per site (for both months), assume $50/hr. Assume flow meter provided by consultant.
Hobo Weather Station: $1,200
Data analysi:s $65,000 To build calibrated and validated model, professional environmental consulting firm with expertise in QUAL2K modeling
Misc. supplies: $5,000 vehicle gasoline, filters, syringes, Aquarods, etc., contingencies
QUAL2K Model, TOTAL: $113,635
ISS = inorganic suspended sediment, TSS = Total Suspended Solids, AFDM= Algal Ash Free Dry Mass, Alk = Alkalinity, TOC =T otal Organic Carbon
GRAND TOTAL, Emperical
Approach (include biological
characterization):
$106,120 This could be as low as $X if the minimum sites were sampled.
GRAND TOTAL, QUAL2K Model
Approach (include biological
characterization):
$188,855 This is an estimate only. Could be lower if data from biological characterization can be used to build the model, could be more if calibrating and validating the model costs more than my data analysis
estimate.
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1
AMENDMENT NO. 7 TO
PROFESSIONAL SERVICES AGREEMENT
FOR
BOZEMAN WASTEWATER TREATMENT PLANT PHASE I
IMPROVEMENTS
THIS IS AN AGREEMENT made as of , 2016 between THE CITY OF BOZEMAN, a Municipal Corporation, P.O. Box 1230, Bozeman, Montana, 59771-1230
(OWNER) and HDR Engineering Inc, 8404 Indian Hills Drive, Omaha, NE 68114-4098,
(ENGINEER).
WHEREAS the parties previously entered into a Professional Services Agreement dated April 9, 2007 herein referred to as the Original Agreement and amended on December 1, 2008,
herein referred to as Amendment 1; amended July 16, 2012, herein referred to as Amendment 2;
amended on February 25, 2013, herein referred to as Amendment 3; amended on December 8,
2014, herein referred to as Amendment 4; and amended on April 20, 2015, herein referred to as Amendment 5; and amended on January 25, 2016, herein referred to as Amendment 6 for professional engineering services for the Bozeman Wastewater Treatment Plant Improvements;
and
WHEREAS, the scope of the Original Agreement included preliminary design and design engineering services, Amendment No. 1 included construction services, Amendment No. 2 included TMDL Technical Assistance; Amendment No. 3 included additional software
programming and additional construction observation, startup and observation services
associated with repair of Digester No. 3 and extension of the construction period for the Digester
No. 3 and Solids Handling Building (Phase 3) Project; Amendment No. 4 included additional corrective action assistance and startup and observation services associated with repair of Digester No. 3, design and procurement assistance with correction of leaking digester mixer
seals at Digester No. 1 and Digester No. 2 and additional follow-on technical assistance to the
City of Bozeman regarding the Montana DEQ’s East Gallatin TMDL process; Amendment No. 5
to add additional follow on services for the TMDL Technical Services, Amendment No. 6 to add additional construction contract services (Tasks 2000 – 2006) and
WHEREAS, the parties desire to amend provisions of the Original Agreement,
Amendment No. 1, Amendment No. 2, Amendment No. 3, Amendment No. 4, Amendment No. 5, Amendment No. 6 add additional follow on services for the TMDL Technical Services for Amendment No. 7.
WHEREAS, the parties desire to amend provisions of the Original Agreement,
Amendment No. 1, Amendment No. 2, Amendment No. 3, Amendment No. 4, Amendment No. 5, and Amendment No. 6 to
NOW, THEREFORE, IN CONSIDERATION OF THE MUTUAL COVENANTS
CONTAINED HEREIN, the parties agree as follows:
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ARTICLE 1 – ENGINEERING SERVICES Section 1.1 is amended to include the attached Exhibit A.
Article 6 - Compensation For Engineering Service
Article 6.2.5 is added as follows:
“6.2 DIRECT LABOR COST PAYMENT FOR BASIC SERVICES AND EXPENSES OF ENGINEER.
6.2.5 The OWNER shall pay an amount for additional follow-on TMDL
Technical Services rendered by the ENGINEER on the basis of the ENGINEER'S
Direct Labor Costs times a factor of 3.15 in an amount not to exceed $91,000.”
Except as specifically amended herein, the Original Agreement and Amendment Nos. 1-6 shall
remain in full force and effect and the parties shall be bound by all terms and conditions therein.
In witness whereof, the Parties hereto do make and execute this Agreement.
CITY OF BOZEMAN, MONTANA HDR ENGINEERING, INC.
BY:________________________ BY:_________________________
(City Manager) Amanda B. McInnis – Vice President
DATE:_____________________ DATE:________________________
ATTEST:
BY:______________________
(City Clerk)
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EXHIBIT A SCOPE OF SERVICES CITY OF BOZEMAN, MONTANA TECHNICAL ASSISTANCE WATER QUALITY
BACKGROUND
DEQ classifies the East Gallatin River as not supporting beneficial uses and as impaired by multiple probable causes.
• Excess algal growth
• Low flow alterations
• pH
• Nitrogen (total)
• Phosphorus (total)
• Alteration in stream-side or littoral vegetative covers
DEQ has completed a total maximum daily load (TMDL) for nitrogen and phosphorus. These
impairments and the TMDL impact the City of Bozeman’s management of their water resources,
storm water, and wastewater. DEQ uses the water quality information to set the City’s Montana Pollutant Discharge Elimination System (MPDES) permit for their publically owned treatment
works (POTW) that discharges to the East Gallatin River.
The City has identified these concerns and has undertaken efforts to understand water quality dynamics in the watershed. The City has supported data collection and the preliminary
construction of river water quality models that represent a single day in the summer of 2012 and
2014. The City recognizes the water quality challenges in the watershed and anticipates that continued active involvement in understanding these issues will help guide decision making.
OBJECTIVES
1. Analyze, and model river and watershed water quantity and water quality so that the City
understands the regulatory implications of wastewater treatment and other management alternatives. 2. Provide data and model(s) at standards that meet DEQ requirements and can be
integrated into DEQ’s decisions on permitting.
SCOPE OF SERVICES
This scope of services is for the Consultant to assist the Owner through various technical assistance activities related to watershed water quality. The proposed scope of Consultant
services are identified in the following tasks. Consultant will commence with services upon
written notice to proceed with the selected tasks. Schedule will be determined at the time of notice to proceed.
TASK 100 - 2015 PRELIMINARY WATER QUALITY MODELING
Objective and Approach
Apply water quality data collected in 2015 to the preliminary QUAL2K water quality model of the
East Gallatin River for 2012 and 2014. The approach involves the following:
• Develop a water balance for the single late summer date representative of the 2015 water quality data based on the data organization.
• Include point source effluent inputs for flow and concentration.
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• Organize the collected water quality data into the model format.
• Compare the 2012, 2014 and 2015 models and examine differences in nutrient concentrations.
• Simulate nutrient reductions (up to 10 scenarios) using the 2015 model and make graphical or tabular comparisons with the results from the 2012 and 2014 models.
Assumptions
• The modeling will not include calibration and validation. The 2012 and 2014 models will be
used as the basis for the 2015 model.
• Data for the East Gallatin River physical conditions and water quality and POTW effluent will
be readily available via the internet or provided by the Owner.
Deliverables
• Brief written summary (in a Word file) with minimal documentation (data sources and a few
paragraphs about the modeling) of the model application, simulation results, and interpretation.
TASK 200 - 2015 EAST GALLATIN RIVER DATA ASSESSMENT REPORT
Objective and Approach
Examine the 2015 water quality data and generate a report similar to the previous assessment
report. The approach involves the following:
• Develop graphs and tables to assess the water quality data.
• Perform the benthic macroinvertebrate and diatom community analysis.
• Examine and update data gaps, conclusions, and recommendations regarding water
quality data and issues.
Assumptions
• The outline and analysis processes are similar to the previous report.
Deliverables
• 2016 East Gallatin River Data Assessment Report (in a Word file) in a format similar to the
previous report.
TASK 300 - ADVANCE THE WATER QUALITY MODELING
Objective and Approach
The preliminary water quality modeling has not been calibrated or validated. These steps will be required by DEQ to change determinations on impairment or permitting. Therefore, refining the
water quality modeling involves the following:
• Refine the water quality models and perform DEQ-required calibration and validation.
Assumptions
• Sufficient data exists to refine the models to meet DEQ’s calibration standards.
• DEQ’s requirements will not vary from the process outlined for the mechanistic approach to
site specific nutrient criteria in the document “Recommendations for Sampling and Modeling the East Gallatin River to Accomplish Multiple Objectives (Dec, 2012)”. All necessary
sampling to ensure the model is to the level acceptable by DEQ is assumed to have been included in this document.
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• Modifications made to the Sampling and Analysis Plan for 2014, 2015, and 2106 will not
negatively impact DEQ’s ability to accept the water quality model because Dr. Suplee was involved in discussions and approval of the SAP’s.
• Budget includes three (3) meetings with DEQ to validate and corroborate the model.
• Limited “what if” scenarios are included in this task, but additional analysis and scenarios
can be run on a time and materials basis based on the City’s objectives as methods for
compliance with water quality standards become more apparent.
Deliverables
• Written modeling documentation (in a Word file) of the model application and simulation results that meet DEQ’s requirements for modeling projects.
• Qual2K model files
TASK 400 - PERMIT RENEWAL ASSISTANCE ON-CALL
Objective and Approach
To assist the City of Bozeman with their MPDES permit renewal through DEQ. Help on an as-needed basis. It is anticipated that this will include multiple meetings with DEQ as well as
phone discussions. HDR is prepared and willing to provide technical solutions to the permit
renewal and write comment letters on behalf of the City.
Also included is a brief white paper outlining the City’s options for compliance with the DEQ
permit. The alternatives include:
1. No Action 2. General Variance
3. Water Quality Site Specific Variance
Assumptions
• Charges will be on a time and materials basis and the overall budget may be extended as
required and requested by the City.
Deliverables
• Permit Strategies white paper
• Meeting minutes
• Comment letters
BUDGET
Task Title Budget
100 2015 Preliminary Water Quality Modeling $2,500
200 2016 East Gallatin River Data Assessment Report
$3,500
300 Advance the Water Quality Modeling $80,000
400 Permit Renewal On-Call $5,000
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