Storm Water Pollution Prevention Plans

Size: px

Start display at page:

Download "Storm Water Pollution Prevention Plans"

Merilyn Cunningham
7 years ago
Views:

1 Storm Water Pollution Prevention Plans

2 Preparation and Cost Implications for Development of Stormwater Pollution Prevention Plans for Landfill Construction Due to Changes in the Construction General Permit Presenter: Gino Nguyen, P.E., QSD

3 Presentation Overview History Summary of Permit Changes SWPPP Risk Assessment Sample Risk Assessment Typical BMPs Cost Implications BMP Follies

4 History 1972 Clean Water Act Prohibits Discharge of Pollutants to Waters of the US 1990 EPA requires compliance with NPDES permit for construction projects disturbing 5 or more acres 1999 EPA lowered acreage to 1 or more acres September 2, 2009 SWRCB Adopted new CGP July 1, 2010 New CGP Order No DWQ becomes effective September 2011, QSD and QSP certifications required September 2012 Post Construction BMP Maintenance Plan takes effect (5 years)

5 Summary of Permit Changes SMARTs Database to streamline application, monitoring, tracking, and reporting SWPPP documents (available to general public) Mandated training and certifications for SWPPP developers and practioners (QSD, QSP) effective September 2011 Risk Evaluation for SWPPPs (Sediment and Receiving Water) LUP vs. Traditional SWPPPs Mandatory sampling for Risk Level II and higher Site Specific

6 SWPPP Risk Assessment Assess project for SWPPP requirements (>= 1 acre of disturbance) Does project qualify for a waiver (Between 1 & 5 acres), R<5 Risk Assessment Sediment and Receiving Waterbody Risk Sediment Risk RUSLE Equation. Based on R, K, LS factors (C and P factors set to 1 for bare soil) R Rainfall Erosivity Value (average annual sum of the total storm kinetic energy times the maximum 30-min intensity for storm events during a rainfall record of at least 22 years)

7 SWPPP Risk Assessment Isoerodent maps developed for Western US ator.cfm R value based on location and construction dates K soil erodibility factor Soil or surface material susceptibility to erosion Transportability of sediment Amount or rate of runoff given a particular rainfall input (ranges from )

8 SWPPP Risk Assessment LS Effect of topography on erosion Hillslope-length factor, L Hillslope-gradient factor, S Receiving Waterbody Does project discharge to a 303(d) listed waterbody impaired by sediment OR does disturbed area discharge to a waterbody with beneficial uses of SPAWN & COLD & MIGRATORY Yes indicates to a HIGH receiving water risk for traditional projects, MED or HIGH for linear projects

9 SWPPP Risk Assessment Risk I, II, or III Combined Risk Level Matrix Receiving Water Risk Sediment Risk Low/Med Low Level 1 Level 2 High High Level 2 Level 3

10 Sample Risk Assessment - R

11 Sample Risk Assessment - K Image from Google Earth Pro

12 Sample Risk Assessment - LS Image from Google Earth Pro

13 Sample Risk Assessment Combined Sediment Risk Factor Worksheet Entry A) R Factor (from EPA Calculator) Analyses of data indicated that when factors other than rainfall are held constant, soil loss is directly proportional to a rainfall factor composed of total storm kinetic energy (E) times the maximum 30-min intensity (I30) (Wischmeier and Smith, 1958). The numerical value of R is the average annual sum of EI30 for storm events during a rainfall record of at least 22 years. "Isoerodent" maps were developed based on R values calculated for more than 1000 locations in the Western U.S. Refer to the link below to determine the R factor for the project site. B) K Factor (weighted average, by area, for all site soils) (from Google Earth) The soil-erodibility factor K represents: (1) susceptibility of soil or surface material to erosion, (2) transportability of the sediment, and (3) the amount and rate of runoff given a particular rainfall input, as measured under a standard condition. Fine-textured soils that are high in clay have low K values (about 0.05 to 0.15) because the particles are resistant to detachment. Coarse-textured soils, such as sandy soils, also have low K values (about 0.05 to 0.2) because of high infiltration resulting in low runoff even though these particles are easily detached. Medium-textured soils, such as a silt loam, have moderate K values (about 0.25 to 0.45) because they are moderately susceptible to particle detachment and they produce runoff at moderate rates. Soils having a high silt content are especially susceptible to erosion and have high K values, which can exceed 0.45 and can be as large as Silt-size particles are easily detached and tend to crust, producing high rates and large volumes of runoff. Use Site-specific data must be submitted. Use the K Factor Google Earth kmz file as provided by the SWRCB. Site-specific K factor guidance C) LS Factor (weighted average, by area, for all slopes) (from Google Earth) K Factor Value 0.32 The effect of topography on erosion is accounted for by the LS factor, which combines the effects of a hillslope-length factor, L, and a hillslope-gradient factor, S. Generally speaking, as hillslope length and/or hillslope gradient increase, soil loss increases. As hillslope length increases, total soil loss and soil loss per unit area increase due to the progressive accumulation of runoff in the downslope direction. As the hillslope gradient increases, the velocity and erosivity of runoff increases. Use the LS Factor Google Earth kmz file as provided by the SWRCB. LS Table LS Factor Value 0.65 Watershed Erosion Estimate (=RxKxLS) in tons/acre Site Sediment Risk Factor Low Sediment Risk: < 15 tons/acre Medium Sediment Risk: >=15 and <75 tons/acre High Sediment Risk: >= 75 tons/acre Low

14 Typical Best Management Practices (BMPs) The following section shows the standard BMPs used on typical construction projects All BMPs will be installed prior to any earth disturbance activities All BMPs will be monitored daily and maintained throughout the duration of the project or until stabilization is achieved Scheduling, Preservation of Existing Vegetation, and Dust Control will take place throughout the project limits and duration

15 Stabilized Construction Entrance Minimum of 30 feet wide by 50 feet long, Typically 1 to 3 inch rock

16 Fiber Rolls or Wattles Installation Staked every 4 feet or weighted with sand bags and overlapped 1 foot. Install parallel to contours and place in trench or furrow to minimize sediment

17 Silt Fence Installation Buried a minimum of 6-inches and overlapped 1 foot

18 Dust Control Water Truck or Water Buffalo on site at all times Fugitive Dust Permit for SCAQMD Rule 403 or 403.1

19 Slope Stabilization

20 Slope Stabilization

21 Tracking Control Monitor continuously and clean by hand sweeping or industrial sweeper

22 Fueling Area and Idle Equipment Storage

23 Spill Kit Must be on site at all times includes vermiculite, absorbent pads, booms, plastic sheeting, shovel, and broom

24 Proper Containment of Chemicals on Site

25 Stockpile Management Stockpiles must be covered and surrounded with wattles each day

26 Stockpile Management

27 Portable Restrooms Must be double contained and anchored for high winds

28 Concrete Clean Out Areas Must be removed from site when 75% full and covered each night REQUIRED ON ALL CALTRANS PROJECTS

29 Storm Drain Inlet Protection Must be weighted with sand bags and maintained throughout project

30 Storm Drain Inlet Protection

31 Conduct Daily Inspections of Equipment and Vehicles

32 Contain all Trash in Covered Bins or Remove Daily

33 Preserve Existing Vegetation

34 Dewatering Must have permit for all dewatering operations

39 SWPPP Training of Personnel All new personnel are required to be trained the first day on site. All personnel will complete a sign in sheet and this will be kept in SWPPP manual Approximately 0.5 to 1 hour training

40 Monitoring and Documentation Review and keep SWPPP updated Visual monitoring will be documented daily of BMP compliance (Visual Monitoring Form). Fill out Monitoring Reports Weekly (Inspection Check List) in SWPPP and after every storm event and keep filed with SWPPP. Photos will be taken by the Contractor to document BMP containment during every storm events. Photos will be taken, prior to, during, and after this storm event and will be submitted to the SWPPP Inspector for submittal to the RWQCB. Rain gauges will be provided by the SWPPP inspector and installed by the contractor on all SWPPP projects. The rain gauges will be photographed after all storm events and the total rain in inches will be documented in your monitoring reports Any changes to construction procedures will need to be amended to the original SWPPP document (Contractor to notify QSD). Any spills or unauthorized releases shall be immediately communicated to SWPPP Personnel so proper notifications can be conducted, if required. SWPPP Inspections conducted periodically by inspection personnel. These inspections shall be printed out and filed in the SWPPP manual. SWPPP MANUAL MUST BE ON SITE AT ALL TIMES

41 Annual Reports, Notice of Termination, and Retention of Records Annual Reports and Certification (September 1) Notice of Termination (upon project completion and submitted to SMARTs) Retention of Records (minimum of 3 years submit to the SWPPP preparer at completion of project, then the manual will be submitted to owner for filing with the construction documents)

42 Cost Implications Risk Analysis for all SWPPPs Additional monitoring, reporting, and sampling Mandatory sampling for Risk Level II and III Must sample each discharge point Must sample for Qualifying Rain Event (0.5 inches or more in 48 hrs) Rain Event Action Plans (REAP) for Risk II and III Annual Report due September 1 every year Possible Bioassessment and Receiving Water body sampling for Risk III Post Closure BMP Maintenance Plan (5 Years)

43 Cost Implications Detention/Infiltration Basins Trenches Vegetated Swales Grading Improvements Storm Water Infrastructure Landscaping

44 BMP Follies

45 BMP Follies

46 BMP Follies

47 BMP Follies

48 BMP Follies

49 BMP Follies

50 QUESTIONS Contact Information: Gino Nguyen, CH2M HILL

Activity Yes No N/A Notes

Activity Yes No N/A Notes CE 2020 (Rev. 12/11) Page 1 of 5 PROJECT NAME AND SITE ADDRESS: CONTRACT NUMBER: ORACLE NUMBER: WDID NUMBER: CONTRACTOR NAME AND ADDRESS: PROJECT SITE RISK LEVEL: Risk Level 1 Risk Level 2 Risk Level 3