HomeMy WebLinkAboutStormwater Permit - IDDE LanguagePage 10 of 38
Permit No.: MTR040000
3. Illicit Discharge Detection and Elimination (IDDE)
a. The permittee shall:
i. Develop, implement and enforce a program to detect and eliminate illicit
discharges (as defined in ARM 17.30.1102(7)) into the permitted Small MS4;
ii. Develop, and keep updated, a storm sewer system map, showing the location and
number of all outfalls (as defined in ARM 17.30.1102(14) and Part VI. of this
General Permit), and the names and location of all surface waters that receive
discharges from those outfalls. Development of this map to accommodate the
provisions of a complete IDDE program and the S WMP would typically include
mapping storm sewer system components including inlets, open channels,
subsurface conduits /pipes, dry wells (discharges to ground water directly), and
other similar discrete conveyances. The permittee must provide a copy of the
developed map(s) or any updates to the Department with the next annual report
required under Part IV.I.;
NOTE: To differentiate between the terms "municipal separate storm sewer"
and "surface water ", and only for the purposes ofdetermining "outfall"
locations with respect to Part H. A3. of this General Permit, the
Department provides the following clarification. If the ephemeral
stream (drainage) has been used (altered, constructed, depended upon,
maintained, etc.) to manage rainfall or snowmelt storm water runoff
from any areas developed for any purpose, then consider it part of the
"municipal separate storm sewer". Also, natural ephemeral streams
which drain into the aforementioned storm water conveyances in the
preceding sentence would also need to be considered part of the
"municipal separate storm sewer ". Other natural and unaltered
ephemeral streams which do not drain from any areas developed for any
purpose, and which drain directly into downgradient intermittent (has a
ground water component) surface waters or into perennial surface
waters would not be considered apart of the "municipal separate storm
sewer". Of course, downgradient intermittent and perennial surface
waters are not considered apart of the "municipal separate storm
sewer "for the purposes of determining "outfall " locations.
Consequently, formal "outfall" locations would then be where
"municipal separate storm sewer" components discharge into
downgradient perennial waterbodies, intermittent waterbodies, or
natural and unaltered ephemeral streams which do not drain from any
areas developed for any purpose.
Another helpful consideration is that natural or manmade conveyance
structures used solely for transporting storm water which originates
within the designated MS4 are not "surface water ". An outfall is the
physical location where these conveyance structures discharge
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Permit No.: MTR040000
pollutants or storm water into surface water or where they leave the
boundary of the designated MS4.
iii. To the extent allowable under State, Tribal or local law, effectively prohibit,
through ordinance, or other regulatory mechanism, non -storm water discharges
(except those listed under Part II.B.3.a.vi. below) into the permitted storm sewer
system and implement appropriate enforcement procedures and actions;
iv. Develop and implement a plan to detect and address non -storm water discharges,
including illegal dumping, to the permitted system;
v. Inform public employees, businesses, and the general public of hazards
associated with illegal discharges and improper disposal of waste; and
vi. Address the following categories of non -storm water discharges or flows (i.e.,
illicit discharges) only if the permittee identifies them as significant contributors
of pollutants to the Small MS4: water line flushing, landscape irrigation, diverted
stream flows, rising ground waters, uncontaminated ground water infiltration (as
defined in ARM 17.30.1102(8)), uncontaminated pumped ground water,
discharges from potable water sources, foundation drains, air conditioning
condensation, irrigation water, springs, water from crawl space pumps, footing
drains, lawn watering, individual residential car washing, flows from riparian
habitats and wetlands, dechlorinated swimming pool discharges, and street wash
water (discharges or flows from fire fighting activities are excluded from the
effective prohibition against non -storm water and need only be addressed where
they are identified as significant sources of pollutants to state waters).
vii. The permittee may also develop a list of other similar occasional incidental
non -storm water discharges (e.g. non - commercial or charity car washes, etc.) that
will not be addressed as illicit discharges. These non -storm water discharges
must not be reasonably expected (based on information available to the
permittee) to be significant sources of pollutants to the Small MS4, because of
either the nature of the discharges or conditions the permittee established for
allowing these discharges to the Small MS4 (e.g., a charity car wash with
appropriate controls on frequency, proximity to sensitive waterbodies, BMPs for
the wash water, etc.). The permittee must document, as a part of the S WMP, any
local controls or conditions placed on these discharges. The permittee must
include a provision prohibiting any individual non -storm water discharge that is
determined to be contributing significant amounts of pollutants to the Small
MS4.
b. The permittee shall maintain documentation with respect to the development of a
storm water IDDE program. This documentation must address both the overall
IDDE program and the individual BMPs, measurable goals, and responsible
persons /positions for this program. This documentation must include the following
information, at a minimum:
L Identify how a storm sewer map was developed. Describe the sources of
information used for the maps, and how verifying the outfall locations and storm
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Permit No.: M7R040000
sewer system components with field surveys was performed. Also, describe how
the map will be regularly updated.
ii. Identify the mechanism (ordinance or other regulatory mechanism) used to
effectively prohibit illicit discharges into the Small MS4 and why that
mechanism was chosen.
iii. Identify the appropriate enforcement procedures and actions which are used to
ensure the illicit discharge ordinance (or other regulatory mechanism) is
implemented.
iv. Identify the plan to detect and address illicit discharges to the system, including
discharges from illegal dumping and spills. This plan must include documented
procedures for screening outfails, including frequency. The plan must include
dry weather field screening for non -storm water flows and field tests of selected
chemical parameters as indicators of discharge sources. The plan must also
address on -site sewage disposal systems that flow into the storm drainage
system. The descriptionmust address the following, at a minimum:
(a) Procedures for locating priority areas which include areas with higher
likelihood of illicit connections (e.g., areas with older sanitary sewer lines,
for example) and/or ambient sampling to locate impacted reaches.
(b) Procedures for tracing the source of an illicit discharge, including the specific
techniques the permittee will use to detect the location of the source.
(c) Procedures for removing the source of the illicit discharge.
(d) Procedures for program evaluation and assessment.
v. Identify the plan to inform public employees, businesses, and the general public
of hazards associated with illegal discharges and improper disposal of waste.
Include in this description how this plan will coordinate with the public
education minimum control measure and the pollution prevention/good
housekeeping minimum control measure programs. This plan must identify
measures to train pertinent municipal employees on the illicit discharge program.
vi. Identify who is responsible for overall management and implementation of the
storm water illicit discharge detection and elimination program and, if different,
who is responsible for each of the BMPs identified for this program.
vii. Identify how the success of this minimum control measure will be evaluated,
including how the measurable goals for each of the BMPs were selected.
4. Construction Site Storm Water Runoff Control
a. The permittee shall develop, implement, and enforce a program to reduce pollutants
in any storm water runoff to the permitted Small MS4 from construction activities