For the Seattle Public Utilities South Park Watershed NEBC - - PowerPoint PPT Presentation

Innovative Water Processing Solutions By Water Quality Management Professionals

End-of-Pipe Municipal Stormwater Treatment Pilot Project For the Seattle Public Utilities South Park Watershed NEBC – Stormwater in the Northwest March 8, 2012

• 1. Meet current permit standard of 80% TSS removal
• 2. Choose a solution or technology that can be

easily modified to accommodate possible future requirements

• 3. Process effectively at 11 cfs (5,000gpm)
• 4. Footprint must be 7,000 ft2 or less
• 5. Solution must have low long-term O&M cost

(volumes could be 150Mgal/year+)

~234 Acre Runoff Area

72” Outfall

• Watershed is located in a heavy-use industrial

area; water from street runoff but also sheet flow

• ff many industrial sites
• Network of conveyance lines feed 3-4 primary

trunk lines which feed a holding vault

• Water flows by gravity from vault through 72”
• utfall pipe via a tide-gate system
• Very little elevation difference in the area (top of

high tide is roughly top of the road)

SEATTLE PUBLIC UTILITIES Sampling & Analysis QAPP Automated Samplers Sample Collection Site Logistics GRANITE CONSTRUCTION Site Grading

Water Detention Tanks

WATERTECTONICS Treatment Equipment Consumables Installation Operator Labor

TREATMENT EQUIPMENT Grit Chamber Electrocoagulation* Clarification Media Filtration GAC Filtration PROCESS CONDITIONS Sampling Period Treatment Flowrate WQ CONDITIONS Turbidity/TSS Conductivity

*No pre or post pH adjustment: all pH readings were ~7.7-8.1

• Electrons are being introduced into solution (the

cathode is oxidized and the water is reduced)

• Coagulation is occurring through both ionic

bonding (charge) & covalent bonding (electron pairing)

• Water (H2O) is being cleaved at the cathode
• Hydrogen gas induces electro-flotation
• Free oxygen increases dissolved oxygen levels
• Total and dissolved metals removed through the

formation of metal oxides and metal hydroxides

• Residual solids is reduced (no long-chain polymers

like Chitosan and no counter-ions)

Storm Event Equipment Period Flowrate

• Avg. NTU In
• Avg. NTU Out

1.5.12 GC+EC+CL 12hr 200gpm 271 42.5 1.20.12 GC+EC+CL+SF 12hr 200gpm 146.9 15 1.30.12 GC+EC+CL 24hr 200gpm 100.7 28.5 1.31.12 GC+EC+CL+SF+GAC 10hr 200gpm 36.6 3.5 2.28.12 EC+CL+SF+GAC 12hr 200gpm 69.8 4.6 2.29.12 EC+CL+SF+GAC 12hr 200gpm 93 5.4 3.5.12 EC+CL+SF+GAC 7hr 100gpm 237.1 3.9

Units Influent Effluent Total Suspended Solids mg/L 156 33.2 Turbidity NTU 175 35 Fecal coliform cfu/100mL 250 22 Copper, Total µg/L 42.6 10.1 Copper, Dissolved µg/L 4.5 2.3 Lead, Total µg/L 28.5 5 Lead, Dissolved µg/L 0.2 ND < 0.1 Zinc, Total µg/L 163 41 Zinc, Dissolved µg/L 19 8 Diesel Range Hydrocarbons mg/L 0.57 0.19 Motor Oil mg/L 1.6 0.35 Bis(2-ethylhexyl)phthalate µg/L 1.8 ND < 1 Total PCB’s µg/L 0.125 0.015

100 200 300 400 500 600 700 NTU

Turbidity Reduction

10 20 30 40 50 60 70 80 90 100 9:10 10:20 12:00 13:40 14:40 16:30 17:20 18:20 Percent Removal

% Turbidity Removal

500 1000 1500 2000 2500 9:10 10:20 12:00 13:40 14:40 16:30 17:20 18:20 Microsiemens

Conductivity

Units Influent Effluent Total Suspended Solids mg/L 138 13.3 Turbidity NTU 130 14.4 Fecal coliform cfu/100mL 380 23 Copper, Total µg/L 39.1 7 Copper, Dissolved µg/L 5.4 3.4 Lead, Total µg/L 20.3 1.8 Lead, Dissolved µg/L 0.2 ND < 0.1 Zinc, Total µg/L 159 27 Zinc, Dissolved µg/L 39 10 Diesel Range Hydrocarbons mg/L 0.53 0.13 Motor Oil mg/L 1.8 ND < 0.2 Bis(2-ethylhexyl)phthalate µg/L 1.5 ND < 1 Total PCB’s µg/L 0.073 ND <0.01

50 100 150 200 250 300 10:30 10:50 11:10 11:30 11:50 12:20 12:40 13:10 13:30 13:50 14:00 14:40 15:10 15:40 16:00 16:30 17:10 17:30 17:50 18:10 18:40 19:00 19:20 19:50 NTU Turbidity Reduction

0% 20% 40% 60% 80% 100% 120% 10:30 10:50 11:10 11:30 11:50 12:20 12:40 13:10 13:30 13:50 14:00 14:40 15:10 15:40 16:00 16:30 17:10 17:30 17:50 18:10 18:40 19:00 19:20 19:50 Turbidity Percent Removal

Units Influent Effluent Total Suspended Solids mg/L 44.4 32.7 Turbidity NTU 50.7 27 Fecal coliform cfu/100mL

• Copper, Total

µg/L 18.7 8.7 Copper, Dissolved µg/L 4.4 2 Lead, Total µg/L 11.2 4.1 Lead, Dissolved µg/L 0.6 ND < 0.1 Zinc, Total µg/L 86 42 Zinc, Dissolved µg/L 28 4 Diesel Range Hydrocarbons mg/L 0.23 0.12 Motor Oil mg/L 0.63 0.23 Bis(2-ethylhexyl)phthalate µg/L ND < 1 ND < 1 Total PCB’s µg/L 0.032 0.012

0.0 20.0 40.0 60.0 80.0 100.0 120.0 140.0 160.0 180.0 200.0 2:00 2:30 3:00 3:30 4:00 4:30 5:00 5:30 6:00 6:30 7:00 7:30 9:20 11:00 11:30 12:00 12:40 18:10 19:00 19:50 20:10 21:30 22:20 NTU

Turbidity Reduction

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 2:00 2:30 3:00 3:30 4:00 4:30 5:00 5:30 6:00 6:30 7:00 7:30 9:20 11:00 11:30 12:00 12:40 18:10 19:00 19:50 20:10 21:30 22:20

Percent Removal

• One of the first times we’ve analyzed

electrocoagulation treatment on a large-scale without doing sand filtration

• In removing the sand filtration step, it allowed us

to see that the relationship between metals removal and turbidity/TSS reduction was not direct

• In fact, it appears that the turbidity/TSS

flocculated particles that were associated with the heavy metal/PCB content settled out disproportionately faster than other turbidity/TSS fractions, maybe due to molecular weight, polarity, particle charge, etc.

• Analytical data from last four storm events is still

forthcoming

• Interested to see how adjusting clarification time

and adding carbon filtration affect treatment

• Off-the-shelf weir tanks were used for

clarification on the project; additional effort is needed to design a high-efficiency clarification system; data collected from the pilot should be useful in accomplishing this

• Key advantage is that solids are removed from the

flow of water and not building up on filters

• Mechanical separation processes AND chemical

reactions that improve and speed up treatment

• In passive filtration systems, you can get build-up
• f organic matter which promotes bacterial

growth, which forms bio-films and sub-micron particles that work their way into filter beds and blind them

WaterTectonics 6300 Merrill Creek Parkway Suite C-100 Everett, WA 98203 www.watertectonics.com