TPDES Program & Effluent Limit Guidelines

Transcription

1 TPDES Program & Effluent Limit Guidelines April 11, 2011 Philip Handley Storm Water Construction Supervisor

2 Page 1 Topics TPDES Permit Requirements & Enforcement Construction on the Edwards Aquifer EPA Effluent Guidelines for Construction

3 Page 2 TPDES Permit Filing Fee with TCEQ $325 for paper NOIs - 7 days from the postmark $225 for electronic NOIs - Immediate coverage after confirmation of receipt No Annual billing No SAWS Permit or Fee Bexar Co. now Phase II MS4 program and they have permit and fee

4 Page 3 epermits State of Texas Environmental Electronic Reporting System (STEERS) Must sign up with STEERS Only open to those with TX DL

5 Page 4 SWPPP The Storm Water Pollution Prevention Plan (SWPPP) is a working, dynamic document. The SWPPP describes to you: What to do How to do it When to do it Currently to Maximum Extent Practical (MEP) design standard

6 SWPPP Page 5 SWPPP must contain information that meets the requirements of the TPDES Construction General Permit TXR150000: Site Description Erosion and Sedimentation Controls Stabilization Practices Structural Control Practices Permanent Storm Water Controls Other Controls

7 Page 6 SWPPP SWPPP must contain information that meets the requirements of the TPDES Construction General Permit TXR150000: Approved State and Local Plans (example WPAP) Maintenance Inspection of Controls Non-Storm Water Discharges

8 Page 7 SWPPP Reporting Inspections must be conducted: At least once every fourteen (14) calendar days AND within twenty four (24) hours of the end of a storm event of 0.5 inches or greater. OR At least once every seven (7) calendar days, on a specifically defined day, regardless of whether or not there has been a rainfall event since the previous inspection.

9 Page 8 SWPPP Signatory Requirements Notice of Intent or Construction Site Notice requires signature Meet signatory requirements in the manner required by 30 TAC Engineer Seal or other Certification Seal not currently required for SWPPP in San Antonio Bexar Co. S.W. Program requires Engineer Seal on SWPPP.

10 Page 9 SWPPP Inspection Report

11 Page 10 Inspector Qualifications Permit, Page 3, 7 (a) Inspection of Controls Personnel conducting these inspections must be knowledgeable of the general permit, familiar with the construction site and knowledgeable of the SWP3 for site. Changing requirements in future TPDES Permit may require more qualifications (Certification)

12 Page 11 Inspection Delegation of Authority If the inspector does not meet signatory requirements, the inspector can be delegated this authority through a letter of delegation. The letter of delegation, signed by a company official that meets signatory authority, authorizes the inspector to sign the inspection reports.

13 Page 12 SWPPP Reporting Include the Letter of Delegation with the SWPPP

14 Page 13 SAN ANTONIO ORDINANCE STORM WATER COMPLIANCE FOR CONSTRUCTION ACTIVITY

15 Page 14 Ordinance Purpose: To reduce pollutants introduced into the MS4 as required by the State Permit (TPDES Construction General Permit TXR150000)

16 Page 15 Ordinance SAWS designated as enforcement staff Directs use of BMPs on construction sites (all-no acreage/size limit) Requires SWPPPs to be available for on-site for inspection SAWS has authority to enforce within City Limits and 5,000 feet beyond Provides penalties

17 Page 16 Ordinance Field Correction Notice

18 Ordinance Field Correction Notice Page 17

19 Page 18 Ordinance Enforcement A violation may result in a Field Corrective Notice 1st 24 hour period to remove and remediate offending material or comply with compliance action 2nd 24 hour period to install or repair corrective BMPs or ensure action If no action is taken

20 Ordinance Enforcement Page 19 Stop Work Order Results when FCN corrections are not made in a timely manner ALL WORK STOPS

21 Page 20 Edwards Aquifer Primary source of drinking water for San Antonio and the surrounding region Serving approximately 1.7 million people Extends from Williamson County, north of Austin through Kinney County, west of San Antonio

22 Page 21 Edwards Aquifer LEGEND Green=Contributing Zone Light Pink=Recharge Zone Dark Pink=Transition Zone

23 Page 22 Edwards Aquifer Protection Program Regulates activities over the Recharge, Transition and Contributing Zone of the Edwards Aquifer Water Pollution Abatement Plans Required Each operator covered by an Edwards Plan must maintain a copy of the approved plan and the approval letter for that plan on-site

24 Page 23 Edwards Plans All plans are required to be developed in accordance with the Edwards Aquifer Protection Program rules and Guidance Documents Portions of the plans need to be signed and sealed by Professional Engineers and Geologists licensed by the State of Texas

25 Page 24 Inspection Frequency Every 7 days and after each ½ inch rain fall Daily inspections may be warranted when sensitive features are located on or adjacent to the site

26 ELG & Changes coming for MS4 s With EPA rule on Effluent Limit Guidelines (ELG) changes will occur with SW Permits & how MS4 s will need to manage SWPPP & NPDES Page 25 SWPPP design moves from Maximum Extent Practical to Performance Based Design

27 Page 26 USEPA ELG for Construction Sites Effluent Limit Guidelines (ELG) for construction and development sites All Industries have identified discharge limits on various constituents based on characterization of their operation function Construction Industry-had none EPA decided to remove ELG from requirement, got sued for action, then required by Fed. Court to develop ELG

28 ELG For Construction Chronology of events: Dec EPA issues numeric limit for turbidity-final Effluent Guideline Rule for Construction and Development Established National Monitoring Requirement Enforceable Numeric Limitations on Storm Water Discharge (Turbidity-280 NTU) NTU: Nephelometric Turbidity Units Page 27

29 ELG for Construction-Chronology Page (later in the year after rule promulgated). EPA withdrew the limit to correct calculation errors identified by petitions filed by Small Business Administration and the National Assoc. of Home Builders

30 ELG for Construction-Chronology Dec Page 29 EPA submitted a proposed Rule to revised turbidity limit to the Office of Management and Budget (OMB) 2011 EPA recently withdrew this proposal from OMB EPA decided to seek additional treatment performance data before proposing a revised turbidity limit

31 ELG for Construction-Chronology Jan.3, 2012-EPA published Fed. Register notice requesting additional data from development sites before proposing a revised Turbidity Limit Page 30 Jan. 4, 2012-EPA Stayed the numeric limit of 280 NTU published in Dec. 1, 2009, Const. & Develop. ELG FUTURE: EPA will propose a revised limit in a future rule making

32 ELG-What is going on? Page 31 Turbidity

33 ELG-What is going on? Page 32 What is the complication? Turbidimeters: EPA Standard Methodologies are for Table Turbidimeters and field sampling will be conducted with portable Turbidimeters.

34 ELG-What is going on? Storm Water Technology (BMP s) ASTM standards for S.W. BMP s-no turbidity data Testing laboratories (Universities) test S.W. BMP s by measuring total percentage of sediment retained in controlled lab testing Re-tooling the Testing Industry Create S.W. BMP Tool Box of data Page 33

35 Page 34 Texas A&M Texas Transportation Institute

36 ELG and SWPPP Design With the EPA ELG Rule, design of SWPPP will move from designs of Maximum Extent Practical To.. Performance Based Design What does this mean? Persons designing SWPPP will now need to utilize storm water and soil engineering expertise (soil/civil engineers, CPESC, etc.) Page 35

37 ELG and SWPPP Design It s about the SOIL! Hydraulics.Manning s Formula/Coefficient Still need it? YES However, you will need to also know: Soil characterization and identification Mechanics of erosion, sediment transport and sedimentation Calculating sediment yields Page 36

38 ELG and SWPPP Design RUSLE Calculations Revised Universal Soil Loss Equation A=(R) (K) (LS) (C) (P) A=Area R=Erosive power of Rain K=Soil Erodibility LS=Land slope and length C=Degree of Soil Cover P=Conservation Practices Page 37

39 ELG and SWPPP Design MUSLE Calculations Modified Universal Soil Loss Equation Developed to relate storm-period sediment yields to upland soil loss rates indexed by USLE erodibility factors and transport efficiency of surface runoff indexed by a function of the product of total storm runoff volume and peak runoff rate. Page 38

40 ELG and SWPPP Design Treatment Train Design to meet discharge Water quality (a future revised NTU) Rain Parameter: most significant factor causing sheet erosion is raindrop impact (typical rain drop is around 1/16 th Inch and travels at terminal velocity of about 18 feet per second) Page 39 Soil Parameter: Shearing force of flowing water is most important in rill and gully erosion

41 ELG and SWPPP Design Page 40 When and how does Erosion begin?

42 ELG and SWPPP Design Raindrop typical size: 1/16 to 1/4 dia. Fall velocity: 18 ft/sec. or about 20 mph Page 41

43 ELG and SWPPP Design Raindrop Impact on Soil (example diagram) Splash Pattern: Page 42

44 ELG and SWPPP Design Erosion Control begins at The source (raindrops impact Bare soil). Page 43 Sediment Control begins down Slope of the erosion source and Terminates in a discharge point/water resource

45 ELG and SWPPP Design Page 44 Light Soils- Smaller granular size Less material but greater turbidity Reading than larger clay soils Dark Soils- Larger granular size More material but clays suspend

46 ELG and SWPPP Design Page 45

47 Guidelines TPDES Program & Effluent Limit Philip Handley Philip Handley Storm Water Construction Supervisor Storm Water Construction Supervisor