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WaterTectonics Presentation for Linked In Regulatory
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- 2. 2 Outline • WT Introduction • Evaluating Construction Projects •Discharge Locations • Permitting • Design Factors • BMPs (Passive vs. Active) • Quick Project Checklist
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- 4. 4 Company Overview • Permanent and Temporary Water Treatment Systems • Hundreds of Treatment Projects Completed Since 1999 –Permitting, Design, R&D – Manufacture, Integrate, Install – Turnkey Operations & Maintenance – Training Courses, Remote Monitoring & Assistance • Based in Everett, WA • 60+ employees
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- 9. 9 Evaluating a Construction Project • Things to Consider: Discharge Location •Regulations • Permits • Discharge Limits Site Characteristics • Soil Type • Rainfall Patterns • Schedule BMPs • Planning • SWPPP Budget
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- 11. 11 Discharge to Surface Water NPDES (aka Construction Stormwater General Permit or CSWGP) • Applicability • Construction Sites disturbing ≥ 1 acre and will discharge stormwater offsite •Sites under an acre that are part of a common plan (residential) • Other sites that may discharge to sensitive areas or have contamination • Requirements • Must comply with permit limits for Turbidity (<25) and pH (6.5‐8.5) • Must have a site‐specific Stormwater Pollution Prevention Plan (SWPPP) • Must have a CESCL perform site inspection weekly and take water quality readings • Additional sampling/treatment required if site has contaminants PROPOSED UPDATES for JAN 1st: • More information required for Contaminated sites • Contaminated sites will use AKART – Active Treatment • Drilled shaft water (no drilling fluids) can be infiltrated • SWPPP Elements (preserving topsoil/LID)
- 12. 12 Discharge to Sanitary Sewer/CSO King County Industrial Waste Discharge Authorization and/or Local Approval • Applicability • Sites discharging to a Combined Sewer •Construction Sites disturbing < 1 acre and will discharge stormwater offsite • Alternate discharge for sites that may discharge to sensitive areas or have contamination • Requirements • Must comply with permit limits for Maximum Daily Volume, Settleable Solids (<7mg/L) and pH (5.5‐12) • Must take Field Measurements (min Flow/Volume, Settleable Solids, pH) every day that discharge occurs • Additional sampling/treatment required if site has contaminants • Must submit monthly reports and pay per gallon fee. Current review time for KCIW permit is at least 4 weeks, double if complex or contaminated site. City of Seattle may hold grading permit until SSPTD is obtained.
- 13. 13 Local Authority • Local Jurisdictions (City/County) – May require specific plans for work during the wet season •Review SWPPP, site plans, geotech, may have formal application pkg – May have more stringent discharge requirements than the State – Allow time for review and approval (4 weeks min) – Administrative fees associated with some approvals City of Redmond – Wet Weather Plan City of Bellevue – Turbidity Monitoring Plan City of Seattle – Drainage Side Sewer Permit $, Dry Season Grading Extension City of Tacoma – Special Authorization to Discharge (SAD) $ King County – Wet Season Plan Snohomish – Enhanced TESC Review
- 14. 14 • Surface Water – Turbidity •25 ntu benchmark • 250 enforcement level – pH • 6.5 – 8.5 – Other as receiving water or past site activity dictates • Sanitary Sewer/CSO – Settleable Solids • <7 mg/L – pH • 5.0 – 11.0 – Other as receiving water or past site activity dictates Discharge Limits 2000 1000 500 100 5
- 15. 15 Site Characteristics • Identify Site Characteristics 1. Rainfall –how much runoff should we plan on? 2. Soil Type (i.e. Particle Size!) 3. Schedule – what time of year will the work take place? 4. Contamination Onsite
- 16. 16 Rainfall • 1” rain on 1 acre of impervious surface = 27,000 gallons • Site Size = 2 acres •1” Storm = Detention Required = 3 tanks (18,000 gallons each) • 2.5” Storm = Detention Required = 8 tanks (135,000 gallons) Confidential & Proprietary
- 17. 17 Soil Type 10000 Gravel 0.016sec 2000 0.4 sec 1000 1.7 sec 600 Coarse Sand 4.6 sec 300 Silt Fence, Ponds 19.0 sec 200 Bioswales 42.0 sec 150 1.25 min 100 Fine Sand 2.8 min 60 Passive filtration 7.8 min 25 Pressurized SF 2.2 hrs 15 Bag Filters 6.2 hrs 10 Silt 14.0 hrs 5 Active Treatment 56.0 hrs 3 CESF/EC 155.3 hrs 1.5 26.0 days 1 Clay 58.0 days 0.1 16 yrs 0.01 Colloidal Particles 1600 yrs Soil Type Time Required to Settle 3ft Particle Diameter (microns) SS/CSO- Settleable Solids Surface Water- Turbidity
- 18. 18 BMPs • Source Control (i.e. Prevention) • Plastic Covering •Mulch • Hydroseeding • Nets & Blankets • Soil Roughening • Terracing • Construction Schedule • Check Dams / Straw Wattles • Outlet Protection • Stabilization Construction Entrances / Exits GOAL = Cover Soils / Slow Velocity! Performance not dependent on particle size
- 19. 19 BMPs • Runoff Control (i.e. Treatment) 1. Detention Ponds / Vaults / Tanks 2.Bioswales 3. Silt Fencing 4. Filter Bags 5. Sand Filters 6. Active Treatment Confidential & Proprietary GOAL = Remove soil particles from water Performance #1‐5 dependent on particle size
- 20. 20 Chitosan Enhanced Sand Filtration (CESF) Electrocoagulation (EC) Approval Level GULDGULD Consumable Liquid Chitosan EC Cells Labor On‐Site Labor When Operating Automated Operator with Alerts Contaminants Turbidity Only Turbidity, Metals, Emulsified Oils Active pH Range 7 to 8 5 to 12 Active NTU Range 0 to 600 0 to 4,000+ Rental Cost (300 gpm) $195 to 225 / day $250 to 310 / day Active Treatment BMPs
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- 23. 23 Case Study • Initial Action • Site had 140,000 gallons of existing storage in a detention vault •Site runoff for 1” storm = 208,000 gallons • 208,000 – 140,000 = 68,000 • Divide by 8 hr shift = 8,500 gallons • Divide by minutes = ~140gpm Influent Turbidity (NTU) Effluent Turbidity (NTU) Effective Particle Size Removal 125 48 63 microns
- 24. 24 Case Study • Intermediate Action • Site could not meet turbidity benchmark •Added sand filter – still only reduced turbidity down to 40 NTU • Submitted sample for particle size distribution Influent Turbidity (NTU) Effluent Turbidity (NTU) Effective Particle Size Removal 48 45 25 microns
- 25. 25 Case Study • Final Action • Particle Size Distributions indicated very small particles •Implemented WaveIonics electrocoagulation system Influent Turbidity (NTU) Effluent Turbidity (NTU) Effective Particle Size Removal 175 5 0.01 microns
- 26. 26 10000 Gravel 0.016sec 2000 0.4 sec 1000 1.7 sec 600 Coarse Sand 4.6 sec 300 Silt Fence, Ponds 19.0 sec 200 Bioswales 42.0 sec 150 1.25 min 100 Fine Sand 2.8 min 60 Passive filtration 7.8 min 25 Pressurized SF 2.2 hrs 15 Bag Filters 6.2 hrs 10 Silt 14.0 hrs 5 Active Treatment 56.0 hrs 3 CESF/EC 155.3 hrs 1.5 26.0 days 1 Clay 58.0 days 0.1 16 yrs 0.01 Colloidal Particles 1600 yrs Soil Type Time Required to Settle 3ft Particle Diameter (microns) Project Planning Quick List • Know the Site • Discharge Location / Limits • Site Characteristics • Rainfall • Schedule • Soil Type • Regulatory Requirements • Get Permits • Identify BMPs to Treat Turbidity/SS & Contaminants if present • Implement BMPs • Work the Plan! • Monitor • Report • Maintain & Adapt
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