15 unit processes and treatability presentation

1

Module 15: Unit Processes for Stormwater Treatment and the

Development of Critical Source Area Controls

Robert PittDepartment of Civil and Environmental EngineeringUniversity of AlabamaTuscaloosa, AL 35487

Introduction

• Pollutants in stormwater are major contributors to degradation of urban streams and rivers.

• Nutrients, organic matter, solids, and trace heavy metals are of concern.

• Knowledge of the fate of pollutants and their association with different particle sizes essential for design of stormwater treatment.

• A heavy metal’s toxicity, bioavailability, bioaccumulation, mobility, and biodegradability can depend on the chemical species.

• Critical source area controls are important components of a comprehensive stormwater management program

• Pollution prevention, outfall controls, better site design, etc., are usually also needed

• In contaminated areas, infiltration should only be used cautiously, after pre-treatment to minimize groundwater contamination

Large parking areas, convenience stores, and vehicle maintenancefacilities are usually considered critical source areas.

2

Storage yards, auto junk yards, and lumber yards

along with industrial storage areas, loading docks, refueling areas, and manufacturing sites.

Common Stormwater Controls

• Public works practices (drainage systems, street and catchbasin cleaning)

• Sedimentation• Infiltration/biofiltration• Critical source area controls• Public education

Stormwater Unit Processes

• Vacuuming and brushing• Evapotranspiration and

evaporation• Chemical volatilization• Reuse on site• Infiltration• Sedimentation• Screening or filtering

• Floatation• Flocculation and

coagulation• Scour• Soil sorption• Plant

sorption/phytoremediation• Biochemical reactions• Ion exchange and sorption

3

Design Modifications to Enhance Control of Toxicants in Wet Detention Ponds

• Settling of fine particulates• Photo-degradation (enhanced vertical

circulation, but not complete mixing that can scour sediments)

• Aeration • Floatation (subsurface discharges) to

increase trapping of floating litter

Catchbasins and Catchbasin Cleaning

Modified inlet to create catchbasin, Ocean County, NJ

VactorTM used to clean sewerage and inlets

Downstream Defender

Proprietary Stormwater Controls (Hydrodynamic Devices) that use Settling for

Treatment and have been Successfully Modeled in WinSLAMM

StormceptorVortechs

Select bypass option in catchbasin controls to describe hydrodynamic device bypass

4

Ponds and filters have been used to treat stormwater in some areas Upflow Filter can be evaluated in WinSLAMM

HydroInternationalUpFloTM

Bar screens and chemical addition are also used at some locations for stormwater treatment

Treatability Testing and the Development of Stormwater

Control Design Criteria

• Particle sizes and settling rates• Relative toxicity after different unit

processes• Laboratory-scale and field pilot-scale tests• Full-scale tests

5

Particle Size AnalysesUsing Cascading Sieves

Particle Size Analyses Using Video Microscope and Computer

Micrograph of Road Surface Sediment Washoff

Approx. 100 µm long

Particle Size Analyses Using Coulter Counter Multi-Sizer 2

6

Coulter Counter Multi-Sizer 3 used to measure particle size distribution of solids up to several hundred micrometers. Larger particles (up to several mm) are quantified using sieves.

Typical Stormwater Particle Size Distributions for Outfall Samples

Measured Particle Sizes, Including Bed Load Component, at Monroe St. Detention Pond, Madison, WI

Particle Size Distribution of Street Dirt

Pitt 1979

7

Particle SettlingRates; Stoke’s andNewton’s Laws

Azur’s Microtox Unit used for Relative Toxicity Measurements

Toxicity using Microtox Test System

8

9

Atomic AdsorptionSpectrophotometer(AAS) With Graphite Furnace, Used for Ultra Low Level Measurements of Heavy Metals

Gas Chromatograph/Mass Spectrophotometer (GC/MSD) used for Organic Toxicant Trace Analyses

Objectives• To determine:

1.If particular nutrients and trace heavy metals are associated with different-sized particles in stormwater.

2. If toxicity of pollutants is related to particle size and if it can be reduced with sequential removal of particulates.

3.Develop the use of Anodic Stripping Voltammetry (ASV) to measure dissolved Zn, Cd, Pb and Cu in stormwater.

Cone splitter: 5 fractions of 1L ea.

Total Solids (100)Metals by ICP-MS (45)Toxicity (40)Turbidity (30)pH (1)Total phosphorus (5)Chemical Oxygen Demand (1)

Min. Needed: 222 mL each fraction (Seven fractions; 272 mL needed for 106µm fraction)

Total Solids (100)TDS and SS (100)Metals by ICP-MS (45)Toxicity (40)Turbidity (30)pH (1)Alkalinity (50)Hardness (100)Total phosphorus (5)Chemical Oxygen Demand (1)Particle size distribution (50)Min. Needed: 522 mL

UV Irradiation

Chelex-100

Toxicity Metals by

ASV

Metals by

ASV

UV

Metals by

ASV

45, 10, 2, 1 µm(222mL min. each)106µm250µm 0.45µm Sequential Extraction

(Min. 300mL needed)

1 2 3 4 5

Original Sample

Unfiltered

10

AfterBefore

Dekaport/USGS Cone Splitter

(Teflon and stainless steel)

SideBottom

Top

After

Large sample volume (about 5 L) separated into subsamples using Delrin® cone splitter. The sample is first poured through a 1500 µm screen to remove leaves and grass clippings, and coarse sediment that would clog splitter. This captured material is also weighed.

Cone Splitter

Delrin® Cone Splitter Trials

0.0340.0490.062COV

33.0947.7559.79STDEV

983.00mL966.00mL965.00mLAVERAGE

97095010609,10

9959509407,8

103010509105,6

9809509853,4

940mL930mL930mL1,2

321Outlet#

Trial

Dekaport/USGS Cone Splitter Test Results for Total Solids (500 mg/L test sediments added to tap water having about 65 mg/L TDS)

1.831.75coef.var (%)10.339.83std

566.12560.26avg.

1.146.5567.9572.4563.3100.130.7560.5561.0560.093.7921.7572.2587.5556.880.120.7573.4572.9573.871.609.1569.8563.4576.261.659.2558.5552.0565.051.478.2555.8561.5550.040.583.2558.3556.0560.632.9216.4561.1572.6549.521.8410.2554.6561.9547.41

coef.var(%)std.avgsecondfirsttube ID

11

Dekaport cone splitter used to separate sample into smaller volumes for different sieve analyses.

All-plastic vacuum filtering setups are used with a series of polycarbonate membrane filters (10, 5, 2, 1, 0.45 µm) to supplement sieves. Effluent after filtering analyzed for a wide variety of constituents.

UV Light Exposure

Dissolved Metals using ASV

• Square Wave Stripping Voltammetry chosen (rapid).

• Allows for the determination of multiple elements in one solution.

• Very low detection limits can be obtained depending upon deposition time.

• Standard additions used to determine unknown concentrations.

Anodic Stripping Anodic Stripping VoltammetryVoltammetry

Metal ions concentrated onto hanging drop mercury electrode by reduction to metallic state:Mn+ + ne- + Hg → M(Hg)

12

Overlay of voltammograms for 1-9 µg/L all metals (in increments of 1 µg/L)using SWSV and 5min deposition.

Zn

Cd

Pb

Cu

Particle Size Distributions

Particle Size (µm)0.45 2 3 5 12.5 20 45 60 90 170 250 1500

0

10

20

30

40

50

60

70

80

90

1001234567891011121314

Cum

mul

ativ

e M

ass

of P

artic

ulat

e S

olid

s(%

Sm

alle

r tha

n S

ize

Indi

cate

d)

Suspended Solids

13

Total Phosphorus Tuscaloosa, AL, Stormwater Outfall SamplesResidual stormwater concentrations after removal of particles larger

than size indicated

Potency Factors of Tuscaloosa, AL, Stormwater Outfall Particulates (mg metal/kg SS)

14,00020029,0002,9000.45 to 2

14,00089019,0004,7002 to 10

1,60023026,00074010 to 45

2,10023015,0001,30045 to 106

3,50038022,0002,100106 to 250

27012029,00050>250

ZincLeadIronCopperParticle size (µm)

UV Light Exposure

14

Average increase of 69%

p = 0.004

Average increase of 62%

p = 0.07

Use of ASV with Chelex resin

• Purpose: to determine concentration of metals in ionic form versus those associated with complexes.

• Resin removes ionic forms of metals.• UV light releases metals from organic

complexes.• Therefore, using Chelex + UV allows for

quantification of ionic forms, organic complexes and inorganic complexes.

5g Chelex-100 resin per 100mL sample. Shake vigorously on shaking table for 1 hour then re-filter.

15

High levels of pollutant reduction require the capture of very fine particulates, and likely further capture of “dissolved”pollutant fractions.

Analyte % Ionic % ColloidalMagnesium 100 0Calcium 99.1 0.9Zinc 98.7 1.3Iron 97 3Chromium 94.5 5.5Potassium 86.7 13.3Lead 78.4 21.6Copper 77.4 22.6Cadmium 10 90

Filtered Sample Ionic and Colloidal Associations

Most of the “dissolved” stormwater metals are in ionic forms and are therefore potentially amenable to sorption and ion-exchange removal processes.

-10

0

10

20

30

40

50

60

70

80

90

100

0 20 40 60 80 100 120

Buffered Aluminum Sulfate (mg/L)

% re

duct

ion

Turbidity

Copper

Lead

Toxicity

Example Stormwater Lead and Copper Reductions using Chemical Coagulation and Precipitation

Alum usually had adverse toxicity effect, while ferric chloride with microsand gave best overall reductions.

FeCl3 additions

Design Modifications to Enhance Control of Toxicants in Wet Detention Ponds

• Settling of fine particulates• Photo-degradation (enhanced vertical

circulation, but not complete mixing that can scour sediments)

• Aeration • Floatation (subsurface discharges) to

increase trapping of floating litter

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Development of Stormwater Control Devices using Media

• Multiple treatment processes can be incorporated into stormwater treatment units sized for various applications.– Gross solids and floatables control (screening)– Capture of fine solids (settling or filtration)– Control of targeted dissolved pollutants

(sorption/ion exchange)

Pilot-Scale Treatment Tests using Filtration, Carbon Adsorption,UV Disinfection, and Aeration

With Fe Cl

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

init ial

aft er FeCl

af ter 100 um

after 25 um

af ter 5 um

af ter ac t. c ar bon

aft er UV

af ter aerati on

Con

cent

ratio

n

Oxmoor

Copper reductions after different treatment stages

Stormwater Toxicant Control• Toxicant removal mechanisms include

sedimentation, biodegradation, volatilization, sorption onto soil particles, and chemical oxidation and hydrolysis

• These processes are available in many urban runoff controls, but modifications should be made in their designs to increase their toxicant removal efficiencies

17

Stormwater Toxicant Control, cont.

• The most effective treatment processes included:

- settling in 1 m column for at least 24 hours (40 to 90% reductions),

- screening through 40 micrometer sieves (20 to 70% reductions), and

- aeration and or photo-degradation for at least 24 hours (up to 80% reductions).

Lab and pilot-scale filters and multi-chambered treatment train (MCTT)

Pilot-scale filters examining many different media.

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The Multi-Chambered Treatment Train (MCTT)

• The MCTT was developed to control toxicants in stormwater from critical source areas.

• Pilot-scale monitoring indicated median reductions of >90% for toxicity, lead, zinc, and most organic toxicants. Suspended solids were reduced by 83% and COD was reduced by 60%.

• Full-scale installations substantiated, or showed improved reductions.

• The MCTT most suitable for use at critical source areas, such as vehicle service facilities, industrial storage and equipment yards, convenience store parking areas, vehicle maintenance areas, and salvage yards.

• The MCTT is an underground device and is typically sized between 0.5 to 1.5 percent of the paved drainage area.

The MCTT is comprised of three main sections:

- an inlet having a conventional catchbasin with litter traps,

- a main settling chamber having lamella plate separators and oil sorbent pillows (and sometimes aeration/dissolved air floatation), and

- a final chamber having a mixed sorbent media (usually peat moss and sand).

Long-term continuous simulations are used to size the unit for specific toxicant reduction goals based on local rain conditions

MCTT Cross-Section

19

Example MCTT Sizing Curves

Milwaukee, WI, Ruby Garage Public Works Maintenance Yard Minocqua, WI, MCTT Test Area

• Minocqua MCTT test site is a 1 ha (2.5 acre) newly paved parking lot for a state park and commercial area.

• Located in a grassed area and was a retro-fit installation.

• Installed capital cost was about $95,000 and included the installation of 3.0 m X 4.6 m (10 ft X 15 ft) box culverts used for the main settling chamber (13 m, or 42 ft long) and the filtering chamber (7.3 m, or 24 ft long).

• Costs are about equal to the costs of installation of porous pavement (about $40,000 per acre of pavement).

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Minocqua, WI, MCTT Installation Minocqua, WI, MCTT Inlet Chamber

Minocqua, WI, MCTT Sedimentation Chamber Minocqua, WI, MCTT Filter Chamber

21

Maintenance of MCTT Units• Major maintenance items for MCTTs

include removal of sediment from the sedimentation basin when the accumulation exceeds 150 mm (6 in.) and removing and replacing the filter media about every 3 years.

• After two wet seasons, the total accumulated sediment depth at the Caltrans installations was less than 25 mm (1 in.), indicating that sediment removal may not be needed for about 10 years.

MCTT Maintenance (cont.)• The sorbent pillows were replaced annually, or

sooner if darkened by oily stains. • Weekly general inspections were conducted

during the wet season for such things as trash removal from the inlet and outlet structures.

• Monthly inspections were also conducted to identify and correct damage to inlet and outlet structures, and to remove graffiti.

• Because the Caltrans MCTT test units were above ground and not initially covered, the permanent pools were available for mosquito breeding. The Via Verde site was finally completely covered with netting to prevent mosquito access.

Pilot-Scale MCTT Pollutant Control by Chamber for Selected Toxicants

99-99Bis (2- ethylhexyl) phthalate

100-100Pyrene916239Zinc1003889Lead967018MicrotoxTM

Overall Device

Peat/Sand Chamber

Main Settling Chamber

Pilot-Scale Test Results

22

Pilot-Scale Test Results Wisconsin Full-Scale MCTT Test Results

>75 (<0.2 µg/L)98 (<0.05 µg/L)Pyrene

>65 (<0.2 µg/L)99 (<0.05 µg/L)Phenanthrene

>75 <0.1 µg/L)>95 (<0.1 µg/L)Benzo (b) fluoranthene

90 (15 µg/L)91 (<20 µg/L)Zinc

nd (<3 µg/L)96 (1.8 µg/L)Lead

65 (15 µg/L)90 (3 µg/L)Copper

>80 (<0.1 mg/L)88 (0.02 mg/L)Phosphorus

85 (10 mg/L)98 (<5 mg/L)Suspended Solids

Minocqua (7 events)

Milwaukee (15 events)

(median % reductions and median effluent quality)

Caltrans Full-Scale MCTT Test Results

82 (171 MPN/100 mL)Fecal coliforms

85 (210 µg/L)Total petroleum hydrocarbons

85 (13 µg/L)Zinc

50 (3 µg/L)Lead

38 (5 µg/L)Copper

39 (0.11 mg/L)Total Phosphorus

35 (0.82 mg/L)TKN

80 (6 mg/L)Suspended solids

Mean % reductions and mean effluent quality

Water Environment Research Foundation (WERF) project on Metals Removal from Stormwater

Main Project Goals:• Contribute to the science of metals’ capture from urban

runoff by filter media and grass swales.• Provide guidelines to enhance the design of filters and

swales for metals capture from urban runoff.

Media Filtration Goals:• Characterize physical properties• Assess & quantify ability of media to capture metals• Rank media & select media for in-depth study• Evaluate effect of varying conditions on rate and extent of

capture• Laboratory- and pilot-scale studies of pollutant removal• Disposal issues of used media (using TCLP)

23

Treatment Media Examined during WERF Study

• Traditional Media– Ion Exchange Resin– Granular activated

carbon (GAC)– Sand

• Other Low Cost (disposable) media– Compost– 2 Zeolites – Iron Oxide Coated Sand– Agrofiber– Cotton Mill Waste– Peat-Sand Mix – Kudzu– Peanut Hull Pellets

•• Metals ExaminedMetals Examined- Copper, Cadmium, Chromium, Zinc, Lead, and Iron

Laboratory Media Studies • Rate and Extent of Metals Capture– Capacities

(partitioning)– Kinetics (rate of

uptake)

• Effect of pH & pH changes due to media, particle size, interfering ions, etc

• Packed bed filter studies

• Physical properties and surface area determinations

Cation Exchange Capacities for Different Media

3.5Sand

9.4Agrofiber

3.8Cotton Waste

6.9Zeolite

5.4Activated Carbon

19Compost

22Peat Moss

CEC (meq/100 g)

Contaminant Losses during Anaerobic vs. Aerobic Conditions between Events

24

Pilot-Scale Downflow Filtration Setup

Media Investigated:• Activated Carbon• Zeolite• Sand• Lightweight Sand• Loamy Soil• Municipal Leaf

Compost• Peat Moss• Kenaf Fiber• Cotton Textile Waste

Pilot-Scale Filtration Setup after Pre-Treatment by Stormwater Pond

25

Clogging Problems Originally Addressed by Pre-Treatment. What about Upflow Filtration?

Expected Advantages:• Reduced Clogging: Sump

collects large fraction of sediment load.

• Prolonged Life: Particles trapped on the surface of the media will fall into the sump during quiescent periods.

• High Flow Rates: Since large and heavy solids will be removed by way of settling in the sump prior to encountering the filter,the filters can be operated at higher flow rates.

No sump

With sump

Upflow Filter Design with Sump

Upflow Filters for Metals Removal

Pressure Pressure gagegage

••SumpSump

• Particulate Solids: Good removal (>90%) for all media for all runs.

• Particulate Metals: Generally 80-100% removal for Pb, Zn, Cd, and Fe and 60-95% removal for Cu and Cr.

• Peat had the best removal rates for particulate bound metals. Removal rates of compost and zeolite were about the same.

Main features of the MCTT can be used in smaller units.The Upflow FilterTM uses sedimentation (22), gross solids and floatables screening (28), moderate to fine solids capture (34 and 24), and sorption/ion exchange of targeted pollutants (24 and 26).

Upflow filter insert for catchbasins

Upflow FilterTM patented

Successful flow tests using prototype unit and mixed media as part of EPA SBIR phase 1 project (controlled lab tests). Phase 2 tests recently completed (field tests), and ETV testing just starting.

15 to 20 gpm/ft2

obtained for most media tested

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

0 2 4 6 8 10 12 14

Residence Time, minutes

% R

emov

al Series1Series2Series3

80 to 90% removal of dissolved zinc using sand/peat upflow filtration

0

5

10

15

20

25

0 5 10 15 20

Headloss (inches)

Flow

(gpm

)

26

Test site drainage area, Tuscaloosa, AL (anodized aluminum roof, concrete and asphalt parking areas; total of 0.9 acres)

EPA SBIR2 UpFlowTM Filter tests using Frankenstein 2 prototype

Support material and media

EPA-funded SBIR2 Field Test Site Monitoring Equipment, Tuscaloosa, AL

27

Flow tests (300 gpm) for bypass capacity

Mixed Media (Mn-Z, Bone Char and Peat)

y = 2.6575x - 31.581R2 = 0.9799

0

5

10

15

20

25

30

35

0 5 10 15 20 25

Head (in)

Flow

(gpm

)

9620482Low (5.8)Mix + Mix9142483Mid (15)Mix + Mix8575487High (27)Mix + Mix9716461Low (6.3)Zeo+ Zeo9236482Mid (10)Zeo+ Zeo8475480High (21)Zeo+ Zeo

% SS reduc.

Average Effluent SS

Conc. (mg/L)

Influent SS Conc.

(mg/L)Flow (gpm)

Media (each bag)

Suspended Solids Removal Tests

Zeo: Manganese-coated zeoliteMix: 45% Mn-Z, 45% bone char, 10% peat moss

Performance Plot for Particle Size Distributions

0102030405060708090

100

0.1 1 10 100 1000 10000

Particle Size (um)

% F

iner

Influent PSD50 mg/L High Flow50 mg/L Mid Flow50 mg/L Low Flow100 mg/L High Flow100 mg/L Mid Flow100 mg/L Low Flow250 mg/L High Flow250 mg/L Mid Flow250 mg/L Low Flow500 mg/L High Flow500 mg/L Mid Flow500 mg/L Low Flow

Upflow Filter Mixed Media Tests (Mn-coated Zeolite, Bone Char, Peat Moss)

28

00093 (and larger)000800007000069 (and smaller)

20 gpm/ft2 (tooverflow)

13gpm/ft2

6 gpm/ft2 (or less)

concentration in particle size range (mg/L):

0 to 0.45 µm (TDS)

34628020.8 (and larger)26428010.4

0004.2

0002.1 (and smaller)0.45 to 3 µm

35678040.2 (and larger)35368020.12222228

0064 (and smaller)3 to 12 µm

31688021.2 (and larger)17428010.600354.200352.1 (and smaller)

12 to 30 µm


30 to 60 µm


60 to 120 µm

mg/L

Perc

ent

100806040200

99

95

90

80

70

60504030

20

10

5

1

Mean0.771

84.17 10.81 12 0.402 0.302

StDev N AD P78.25 13.71 12 0.224

VariableInfluent (mg/L)Effluent (mg/L)

Normal Probability Plot of Concentration for Particle Range 0-0.45 um

mg/L

Perc

ent

2520151050

99

95

90

80

70

60504030

20

10

5

1

Mean0.011

5.215 3.384 12 0.500 0.167

StDev N AD P9.36 7.604 12 0.942

VariableInfluent (mg/L)_1Effluent (mg/L)_1

Normal Probability Plot of Concentration for Particle Range 0.45-3 um

mg/L

Perc

ent

6050403020100-10-20

99

95

90

80

70

60504030

20

10

5

1

Mean0.011

9.079 6.691 12 0.693 0.052

StDev N AD P18.07 14.68 12 0.942


Normal Probability Plot of Concentration for Particle Range 3-12 um

mg/L

Perc

ent

302520151050

99

95

90

80

70

60504030

20

10

5

1

Mean0.011

5.148 3.653 12 0.658 0.064

StDev N AD P9.518 7.730 12 0.943



mg/LPe

rcen

t806040200-20

99

95

90

80

70

60504030

20

10

5

1

Mean0.011

1.259 0.3854 12 0.311 0.507

StDev N AD P27.34 22.21 12 0.942



mg/L

Perc

ent

100806040200-20

99.9999

99.99

99

95

80

50

20

5

1

Mean0.011

0.6858 0.9493 12 1.699 <0.005

StDev N AD P19.98 16.23 12 0.942



mg/L

Perc

ent

1086420-2-4

99

95

90

80

70

60504030

20

10

5

1

Mean0.034

* * 10 *

StDev N AD P3.44 2.721 10 0.747



mg/L

Perc

ent

3002001000-100

99

95

90

80

70

60504030

20

10

5

1

Mean0.011

* * 12 *

StDev N AD P113.2 91.94 12 0.942


Normal Probability Plot of Concentration for Particle Range >240 um

29

Mn Coated Zeolite Performance for Particle Size Distribution

01020

3040506070

8090

100

0.1 1 10 100 1000 10000Particle Dia (µm)

% F

iner

HighMidLowInfluent

Performance Plot for Particle Size Distributions

0102030405060708090

100

0.1 1 10 100 1000 10000

Particle Size (um)

% F

iner

Influent PSD50 mg/L High Flow50 mg/L Mid Flow50 mg/L Low Flow100 mg/L High Flow100 mg/L Mid Flow100 mg/L Low Flow250 mg/L High Flow250 mg/L Mid Flow250 mg/L Low Flow500 mg/L High Flow500 mg/L Mid Flow500 mg/L Low Flow

Activated Carbon Performance for Particle Size Distribution

01020

3040506070

8090

100

0.1 1 10 100 1000 10000Particle Size (µm)

% F

iner

HighMidLowInfluent

Bone Char Carbon Performance Plot for Particle Size Distribution

010

2030

405060

7080

90100

0.1 1 10 100 1000 10000Particle Size (µm)

% F

iner

HighMidLowInfluent 10

100

1 10 100 1000

Influent Suspended Solids (mg/L)

% R

educ

tion

70 to 90% SS reductions for influent concentrations >90 mg/L

1

10

100

1000

1 10 100 1000

Influent Suspended Solids (mg/L)

Efflu

ent S

uspe

nded

Sol

ids

(mg/

L)

Effluent SS <100 mg/L whenever influent is <500 mg/L

UpFlow Filter™

Components:1. Access Port2. Filter Module Cap3. Filter Module4. Module Support5. Coarse Screen6. Outlet Module7. Floatables

Baffle/Bypass

1

3

2

45

7

6

Hydro International, Ltd.

30

Upflow Filter Components1. Module Cap/Media

Restraint and Upper Flow Collection Chamber

2. Conveyance Slot3. Flow-distributing

Media4. Filter Media5. Coarse Screen6. Filter Module

1

6

3

4

5

2

3


Hydraulic Characterization

Assembling Upflow Filter modules for lab tests Initial CFD

Model Results

High flow tests


Operation during normal and bypass conditions

31

Draindown between events

ETV test setup at Penn State - Harrisburg

Conclusions• The MCTT provided substantial reductions in

stormwater toxicants (both in particulate and filtered phases) and suspended solids.

• The main settling chamber provided substantial reductions in total and dissolved toxicity, lead, zinc, certain organic toxicants, SS, COD, turbidity, and color.

• The sand-peat chamber also provided additional filterable toxicant reductions.

• The catchbasin/grit chamber is an important element in reducing maintenance problems by trapping bulk material.

Conclusions (cont.)

• The bench-scale treatability tests conducted during the development of the MCTT showed that a treatment train was needed to provide redundancy because of frequent variability in sample treatability storm to storm, even for a single sampling site.

• Possible to develop other stormwater controls that provide treatment train approach.

Conclusions (cont.)

• Upflow filtration with a sump and interevent drainage provided the best combination of pre-treatment options and high flow capacity, along with sustained high contaminant removal rates.

32

Conclusions (continued)

<2037Zinc (µg/L)3 to 1512Lead (µg/L)3 to 1515Copper (µg/L)0.13Cadmium (µg/L)0.80.9 to 1.3TKN (mg/L)

0.02 to 0.10.2 to 0.3Phosphorus (mg/L)

<5 to 1010 to 45Particulate solids (mg/L)

Effluent concentrations with treatment train using sedimentation along with sorption/ion exchange

Reported irreducible concentrations (conventional high-level stormwater treatment)

Constituent and units

References• Barrett, M. Performance Summary Report for the Multi-

Chambered Treatment Trains. Prepared for the California Department of Transportation. May 2001.

• Clark, S., R. Pitt, and R. Raghavan. SBIR Phase 1 report for Upflow Filtration Treatment of Stormwater. U.S. EPA. Publication pending 2003.

• Corsi, S.R., S.R. Greb, R.T. Bannerman, and R.E. Pitt. Evaluation of the Multi-Chambered Treatment Train, a Retrofit Water Quality Management Practice. U.S. Geological Survey. Open-File Report 99-270. Middleton, Wisconsin. 24 pgs. 1999.

• Johnson, P., R. Pitt, S. Clark, M. Urritta, and R. Durrans. Innovative Metal Removal for Stormwater Treatment. Water Environment Research Foundation. Publication pending 2003.

• Pitt, R., B. Robertson, P. Barron, A. Ayyoubi, and S. Clark. Stormwater Treatment at Critical Areas: The Multi-Chambered Treatment Train (MCTT). U.S. Environmental Protection Agency, Wet Weather Flow Management Program, National Risk Management Research Laboratory. EPA/600/R-99/017. Cincinnati, Ohio. 505 pgs. March 1999.

AcknowledgementsWERF Project 97-IRM-2

Project Manager: Jeff Moeller

U.S. EPA Small Business Innovative Research Program (SBIR1 and SBIR2 plus ETV testing)

Project Officer: Richard Field

Many graduate students at the University of Alabama and Penn State-Harrisburg

Industrial Partners (US Infrastructure and Hydro International)

Documents

15 unit processes and treatability presentation