HomeMy WebLinkAboutMPDES SWPPP Admin 8.18_F2/23/2019
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BMP BREAKDOWN –
TREATMENT BMPS
HAVING DONE ALL –YET STILL HAVE DIRTY WATER!
WATER TREATMENT
•WHY WOULD A PROJECT NEED WATER TREATMENT?
•DEFINING ATS & PTS
•WHEN IS IT APPLICABLE?
WHY TREATMENT IS OFTEN NEEDED WHY ACTIVE TREATMENT IS OFTEN NECESSARY:
DESCRIPTION SETTLING TIME
GRAVEL 1 SEC.
9.8 SEC.
COARSE SAND
48 SEC.
FINE SAND 67 SEC.
125 SEC.
47.6 MIN.
SILT 107 MIN.
7.2 HRS.
20.1 HRS.
CLAY
180 HRS.
754 DAYS
COLLOIDAL PARTICLES 207 YEARS
Sometimes soil particles will settle out quickly enough to achieve satisfactory discharge quality.
Frequently, however, they won’t.
WHY FINE CLAYS AND COLLOIDAL PARTICLES
DON’T SETTLE NATURALLY:
These small particles
remain suspended in
stormwater because
of their repellent
charges and small
mass.
e-
e-
e-e-
e-
e-
e-e-
e-
e-
e-e-
THE PROCESSES OF COAGULATION
AND FLOCCULATION:Once suspended
particles are flocculated into
larger particles, they
can usually be
removed from the
liquid by settling,
filtering, or
centrifuging.
Add Coagulant
Flocculation
Neutralizes
electrostatic charge
P+
P+
e-e-
e-e-P+
P+P+
P+
e-e-
e-e-P+
P+
P+
P+
e-e-
e-e-P+
P+
P+
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FLOCCULATION WATER TREATMENT
•THE PROCESSES
•COAGULATION
•FLOCCULATION
•CLARIFICATION
•APPLICATION
•DOSAGE
•PH
•TYPES OF WATER
TREATMENT
•BATCH TREATMENT
CHITOSAN ENHANCED
SAND FILTRATION
(CESF)
•ELECTRO-
COAGULATION
Passive Treatment -PTS
Batch Treatment :Floc’dpollutant
settling via gravity
Active Treatment -ATS
Flow-through Treatment:Floc’dpollutant
filtered
ADVANCED STORMWATER TREATMENT
METHODS –ATS AND PTS
Water is treated as a “batch” to
appropriate levels and then
discharged all at once
•Effective
•Takes large footprint
•Takes time
BATCH TREATMENT
LARGE BATCH SYSTEM
Flow-Through Treatment
1.Water is pumped from a collection point2.The pollutant is floc’dby chemical or current3.The water passes through filtration media 4.Water is discharged or re-circulated
DISCHARGE
Filtration Unit
Recirculation Line
Stormwater
Main
Pond
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ATS Technologies–
•Electrocoagulation
•Cartridge Filtration
•Chitosan Enhanced Sand Filtration (CESF)
FLOW THROUGH ATS TECHNOLOGIES
•SUBTRACTIVE, NON-POLYMER STORMWATER TREATMENT SYSTEM
•USES ELECTRIC CHARGE TO INDUCE
COAGULATION
•HIGHLY EFFECTIVE FOR BASIC AND
ENHANCED STORM WATER TREATMENT
•FLOWRATES FROM 100-500+ GPM
ELECTROCOAGULATION ELECTROCOAGULATION
TWO APPLICATIONS OF CHEMICAL TREATMENT
PASSIVE DOSING LIQUID INJECTION
CARTRIDGE FILTRATION
Can be done with or without
chemistry but struggles
without.
•Media can be very target
specific•Good in low flow situations
•Small footprint
•Filter blinding•Media and flocculant
matching•Media replacement
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Chitosan Enhanced Sand Filtration (CESF)
•CESF technology is able to treat water at high flow rates while
reducing the turbidity levels by 99% or greater.
•CESF technology has been applied to large infrastructure
projects, box store construction, road construction and remediation
sites.
•Versatile and Adaptable to
Different Soil Types
•Extremely Low Turbidities at
High Flow Rates•Controlled Dosing
•Sand Filters Can Crash
•Footprint•Treatability Conflicts
CESF
KEYS TO USE
•DOSING –PASSIVE DOSING NOT ALLOWED UNLESS TO SANITARY,
LIQUID RESTRICTED AT PRESCRIBED RATE
•ONSITE CERTIFIED TECHNICIANS
•REPORTING
•QAPP (QUALITY ASSURANCE PROJECT PLAN)
•OPERATIONAL REQUIREMENTS –DISCHARGE LIMITS, RESIDUAL
CHEMISTRY, ETC.
1. SITE CONSIDERATIONS
•SOIL TYPE
•POTENTIAL POLLUTANT(S)
•ALLOWABLE FOOTPRINT FOR EQUIPMENT AND WATER STORAGE
•PROJECT START DATE
2. PRECIPITATION & SYSTEM SIZING
•DRAINAGE (HISTORICAL RAIN VOLUME, FLOW RATE, ETC.)
•TOTAL VS. INTENSITY
•MINIMUM STORAGE VOLUME
•2 YEAR –6 HOUR EVENT <+PRETREATMENT>
3. DISCHARGE
RECEIVING WATER
303(D) & SENSITIVE HABITAT
STORM SEWER VS. SURFACE DISCHARGE
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4. CHEMISTRY
•TREATABILITY
•“APPROVED” CHEMISTRY
•USE DESIGNATION -DOSING
•RESIDUAL
CONSTRUCTION STORMWATER FILTRATION
PH = NONVISIBLE POLLUTANT
MEASURING PH
PH & AQUATIC LIFE HIGH PH NEUTRALIZATION USING CO2
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NEUTRALIZATION SYSTEMS NEUTRALIZATION SYSTEMS
COST INFLUENCES ON TREATMENT
•SITE CONDITIONS
•PROJECT SIZE•SOIL TYPE
•FACTORS INFLUENCING COSTS
•PHASING OF PROJECT
•RECEIVING WATERS FOR DISCHARGE
•OTHER POLLUTANTS (I.E. PH, ARSENIC, PETROLEUM PRODUCTS)•TREATABILITY OF STORMWATER
OTHER CONSIDERATIONS
IN-FIELD SERVICE: CONTRACTORS SELF PERFORM VS. SERVICE COMPANIES
POTENTIAL CHEMISTRY CONFLICTS –EX. WHEEL WASH
FILTRATION MEDIA CONFLICTS –EX. PAM AND SAND
SELECTING BMPS
BMPS SAVE MONEY
•FULLY IMPLEMENTING BMPS AT ALL LEVELS (DESIGN, OPERATIONS,
PHYSICAL) IS THE EASIEST WAY TO MINIMIZE COSTS.
•ALL PARTIES (FROM DESIGN THROUGH CONSTRUCTION) MUST UNDERSTAND THE VARIABLES, AND WHAT ACTIONS THEY CAN TAKE
TO MINIMIZE COSTS; HOWEVER,
•ALL PARTIES MUST ALSO UNDERSTAND THAT ACTUAL COSTS WILL BE AFFECTED BY SOME VARIABLES OUTSIDE OF THEIR CONTROL:
•ACTUAL RAINFALL
•OFF-SITE ACTIVITIES BY OTHERS
•UNANTICIPATED SOIL CHARACTERISTICS/CONTAMINANTS
•ONGOING CHANGES IN REGULATORY REQUIREMENTS.
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BMP SELECTIONENVIRONMENTAL CONSIDERATIONS
#1 -PROTECT THE ENVIRONMENT AND WATER QUALITY
•BMPS SHOULD OUTLAST LONGEST SCHEDULE AND THE WORST STORM
•CONSIDER PROJECT DURATION
•WASTES GENERATED MUST BE CONSIDERED
•BIODEGRADABLE VS. SOLID WASTE
•MEDIA DISPOSAL AND REPLACEMENT
•SLUDGE –CONTAMINATION AND LAND APPLICATION
BMP SELECTION
ECONOMIC CONSIDERATIONS
•SAVE TIME AND MONEY AND REDUCE THE LIKELIHOOD OF PENALTIES
•MINIMIZE INTERRUPTION IN OPERATIONS AND DECREASE COSTS OF
REPAIRING DAMAGE CAUSED BY EROSION
•PROPER INSTALLATION AND MAINTENANCE CAN HELP CONTROL COSTS OF
REPLACING BMPS
•LOOK AT BOTH LONG AND SHORT TERM COST
BMP SELECTION
OTHER CONSIDERATIONS
•INSTALLATION AND MAINTENANCE MUST BE FACTORED IN AS WELL AS
COST OF MATERIALS
•SOILS, CLIMATE, TOPOGRAPHY AND DURATION OF USE MUST BE EXAMINED
PRIOR TO GROUND BREAKING (BMP PLANNING).
•IT MAY NOT BE APPROPRIATE TO USE A CERTAIN BMP ONCE ALL VARIABLES
ARE FACTORED IN.
PRIORITIZING ESC FOR CONSTRUCTION
SITES
Adapted from KY ESC Field Manual
PRODUCT PERFORMANCE IS AFFECTED BY:
•SLOPE STEEPNESS AND LENGTH
•SOIL TYPE
•TIME OF SEEDING
•DIRECTIONAL EXPOSURE
•WEATHER CONDITIONS
•QUALITY OF INSTALLATION
BMP SELECTION REMINDERS
•PLAN AHEAD!
•DESIGN PROJECT AND BMPS SPECIFIC TO THE SITE CONDITIONS
•MINIMIZE EROSION POTENTIAL FROM DAY 1.
•TIMING•COMPLETE PROJECTS IN PHASES
•DON’T EXPOSE SOIL IN RAINY SEASON IF POSSIBLE
•TAKE TIME FOR PROPER INSTALLATION & MAINTENANCE OF BMPS
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BREAK
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