Changes to the General Construction Permit: New Requirements. Scott Taylor, P.E. RBF Consulting January, 2009

Transcription

1 Changes to the General Construction Permit: New Requirements Scott Taylor, P.E. RBF Consulting January,

2 Overview Permit Overview of requirements Monitoring and Reporting Advanced Treatment Systems Rain Event Action Plans Sample Risk Calculation - Project What You Need to do to Prepare 2

3 Overview Permit takes effect on July 1, 2010, adopted on September 2 nd, 2009 Four phases of construction: Grading, Streets/utilities, Vertical, Post Construction Exempt: Repaving except where underlying soil is disturbed or surrounding soil cleared LUP s: : The permit includes Linear Underground/Overhead Projects modestly different filing and reporting requirements 3

4 Permit Findings Prohibited: Discharge of any debris (including trash) NAL: Turbidity 250 NTU, ph NEL: Turbidity 500 NTU, ph 6-96 Design Storm: 5 year, 24 hr for NEL compliance (RL 3) Exceedance of NEL is a violation of the permit! 4

5 What Will an Exceedance Mean? Superior court can apply civil liability up to $25,000/day and $25/gallon CWA penalty is $37,500/day State or Regional Board may administratively apply a penalty of $10,000/day and $10/gallon MMP The mandatory minimum penalty applies to the NEL exceedance.. On the 4 th exceedance within 6 months, a fine of $3,000 must be assessed. 5

6 Order Section II Conditions Electronic Filing of PRDs NOI Risk Assessment Site Map SWPPP Signed Certification Statement 7 Days prior to construction Send fee separately, site not covered until you receive WDID # LRP or LRP designee All Existing Projects after July 1, 2010 Risk 1 6

7 Order, Con t Small Site Erosivity Waiver 1 to 5 acres disturbed area R less than 5, submit waiver through SMARTS, pay fee Final Stabilization 2.D.1.a. not pose any additional sediment discharge risk than it did prior to the commencement of the construction activity (photos) 70% coverage rule still applies, or: RUSLE2 Method Custom Method (undefined) 7

8 Order Section III File NOT within 90 days of completion Need post-construction BMP maintenance plan Non-stormwater discharge must be monitored for NAL and NEL compliance No discharge to ASBS unless have a valid waiver 8

9 Order Section V. Effluent Stds. 9

10 Order Section IV Must meet TMDL requirements where construction activity or land disturbance is indicated NALs and NELs are compared to a daily average of all samples (3 per day, each location). 10

11 Turbidity Readings - Visual Comparisons Decreasing Turbidity 933 NTU 745 NTU 584 NTU 477 NTU 404 NTU 283 NTU Decreasing Turbidity 4 NTU 44 NTU Readings Above Turbidity NEL 64 NTU 107 NTU 140 NTU 216 NTU Decreasing Turbidity Readings Below Turbidity NEL 11

12 Drop in Turbidity Readings with Time Time = 0 Initial Reading: 663 NTU Time = 1 Minute Reading: 631 NTU Time = 5 Minutes Reading: 574 NTU Time (minutes) Overall Change in Reading (NTU) Time = 10 Minutes Reading: 502 NTU Time = 15 Minutes Reading: 422 NTU *Note: Changes in turbidity readings over time will vary with sediment properties (particle size, weight, 12 etc).

13 Order Section VII - Training SWPPP QSD PE, PG or EG, LA, PH, CPESC or 5 years experience and take approved course w/in 2 years REAP/Implementation QSP Certified inspector QSD And take approved course w/in 2 years 13

14 Order Section VIII Risk Determination/Requirements Three Risk Categories based on site and receiving water risk Risk computation/determination greatly simplified: Assess Site: Compute R, K and LS for project Assess RW: 303(d) listed or COLD, SPAWN and MIGRATORY For Risk 3, must be high for site and RW Risk 14

15 Risk Categories 15

16 Order Section VIII Risk Determination/Requirements Risk Level 1 Risk Determination Appendix 1 Risk Level 1 Requirements (Attachment C) No NELs or NALs B. Housekeeping Cover stockpiled materials not actively being used Must store chemicals under cover (watertight) Cover waste containers end of day and before rain Concrete washouts must be water tight BMPs to prevent trackout. Risk Level1 16

17 Risk Level 1 Con t Discontinue application of any erodible landscape material within 2 days before a forecasted rain Street washing is effectively prohibited Soil cover required for inactive areas (14 days) Design sediment basins to CASQA stds. Run-on: It appears that you own it: Risk Level 1 17

18 Run-on (Section F.) Risk Level 1 dischargers shall evaluate the quantity and quality of run-on and runoff through observation and sampling. Risk Level 1 dischargers shall effectively manage all run-on, all runoff within the site and all runoff that discharges off the site. Run-on from off-site shall be directed away from all disturbed areas or shall collectively be in compliance with the effluent limitations in this General Permit. Risk Level 1 18

19 Runon (Section V.C.4.b) [NAL exceedances] ] that are related to the run-on associated with the construction site location and whether additional BMP measures are required to (1) meet BAT/BCT requirements; (2) reduce or prevent pollutants in storm water discharges from causing exceedances of receiving water objectives; and (3) describe corrective action(s) ) that were taken or will be taken with a description of the schedule for completion Risk Level 1 19

20 Risk Level 1 Con t G. Inspection and Repair: Done by a QSP, each formally documented Inspect weekly (checklist), during rain events other text indicates before/after inspections also required. 72 hrs to effect repairs No REAP required During business hours only Quarterly non-stormwater inspection Risk Level 1 20

21 Risk Level II Additional Risk Level II Requirements ph NAL Turbidity NAL 250 NTU REAPs are required all phases or inactive Provide effective soil cover for inactive areas (14 days) AND appropriate erosion control BMPs (soil stabilization) for active areas Required sediment controls at top/toe and face of slopes to segment them (assumed finished slopes) Risk Level II 21

22 Risk II Additional Requirements Con t Limit traffic to designated entrances/exits Inspect all access roads daily for track out REAP developed 48 hrs prior to forecast event and on site 24 hrs prior to event MUST collect effluent samples Collect 3 samples per day ph and Turbidity Risk Level II 22

23 Risk Level II Sampling Con t Characterize entire disturbed area All points discharging offsite Pick up the worst discharges No sampling if dangerous or outside of business hours, but have to document the reasons Must train personnel to SWAMP QAPP stds. Must sample NSW that discharges off site. Non-visible sampling requirements Can substitute for a regional monitoring program (RB discretion) Risk Level II 23

24 Risk II NAL Exceedences What is required if NAL exceedance: Submit all sampling results to SB w/in 10 days after storm event conclusion RB may require a NAL Exceedance Report which describes the problem and corrective actions taken Examine BMPs and take action to reduce value to less than NAL this is a continuous loop for NAL exceedance Risk Level II 24

25 Risk III - Additional Requirements Risk Level III Requirements NAL and NEL compliance required Erosion and sediment controls ( appropriate( appropriate ) required for all areas during active construction Risk Level III 25

26 Risk III Additional Requirements Regional Board can require additional site specific measures If violate an NEL (ph or turbidity) then sample the receiving waters for ph, turbidity, SSC and others (at Board discretion) for remainder of permit coverage Project greater than 30 acres of DSA and direct discharge will participate in benthic macroinvertebrate bioassessment. Sample u/s and d/s of project during index period Risk Level III 26

27 Risk III Additional Requirements Con t Sampling on inactive sites is required NAL Exceedance Report is similar to RL 2, is a RB discretionary item Submit all sampling data within 5 days of event to SB NEL violation report (QSD( QSD): Submit to SB within 24 hrs after violation identified Document the violation, and the corrective actions Document the rainfall depth (compliance storm) Risk Level III 27

28 Order Section XIII Post Construction Take effect 3 years after adoption date of permit (Sept 2, 2009) Exempt if under a Phase I or II program with an approved SWMP. Replicate pre-project project water balance for 85 th percentile storm Site DSA greater than 2 acres, preserve stream drainage density (stream miles/da) 28

29 Monitoring and Reporting 29

30 Sampling Requirements Current permit requirements continue Types: Visual, Non-visible, Effluent and Receiving Water Visual required for all risk levels Non-visible required for all risk levels Effluent Risk 2 and 3 Only Always Required ph and Turbidity (SSC for RL3 if NEL violation) Receiving Water Risk 3 only with NEL Violation and direct discharge 30

31 New Monitoring Requirements Overview 31

32 Visual Monitoring Dry Weather Requirements apply to each drainage area on site, done quarterly for dry weather flow Visual observations must document: Non-stormwater Visual impairments or odor Must record all inspections, maintain in SWPPP Take corrective action and note in SWPPP Must inspect site weekly for SWPPP compliance 32

33 Visual Monitoring Wet Weather Inspect all discharge locations within 2 business days of event (1/2 rainfall) Inspect all stored runoff All drainage areas for spills, leaks, failures All BMPs for conformance with REAP (RL 2, 3) All BMPs to ensure they are functioning adequately, determine if additional BMPs are needed. Inspect site within 2 days after qualifying event Inspect during event if continues longer than 24 hrs 33

34 Sampling and Analysis Requirements Non-visible The General Permit was previously amended to require a sampling and analysis strategy regardless of whether you plan to sample. Plan must be included in the SWPPP The Requirements apply to all construction sites and all risk levels, and supplement the Visual Monitoring Program also required under the General Permit 34

35 Water Quality Sampling - Effluent 35

36 Water Quality Sampling - Effluent Grab samples from one location in each discharge point from the site Collect samples of stored or contained storm water that is from a storm ½ inch or greater Grab samples must be representative May include a run-on sample 36

37 Receiving Water Monitoring 37

38 Receiving Water Monitoring Risk level 3 Only required if NEL violation at site and direct discharge, then sample for remainder of project Sample upstream and downstream of discharge point: ph, turbidity, SSC Risk level 3 conduct or participate in benthic macroinvertibrate bioassessment prior to start of construction upstream and downstream of site in receiving water Site greater than 30 acres with direct discharge 38

39 Reporting NEL/NAL NEL Violation (RL 3) Electronically submit data within 5 days of receiving information (RL 3) Include data, methods, location, date and time of violation Requires an NEL Exceedence Report submitted within 24 hrs to RB of violation identification NAL Exceedance (RL 2 or 3) Electronically file results within 10 days of storm (RL 2, 3) NAL Report: Include data, methods, location, date and time of exceedance,, corrective actions 39

40 Reporting - Annual Electronically submit by September 1 each year Include: Summary and analysis of all sampling data Summary of all corrective actions Identification of any compliance activities or corrective actions that were not taken A summary of all exceedances and violations of the permit Names of all responsible parties All visual, effluent and receiving water inspection records, including exceptions Personnel training information 40

41 Advanced Treatment Systems 41

42 Advanced Treatment Systems Will effectively require a site operator Requires a written plan and design approved by CPESC, CPSWQ, PE or any other registered engineer Operator must have 5 years of experience or be a Class A contractor Provide ATS plan electronically to Board 14 days prior to operation of ATS. 42

43 ATS Plan ATS operation and maintenance plan Sampling and reporting plan, QC plan Spill prevention plan Health and Safety plan Conduct jar tests to determine coagulant dosage 43

44 ATS Design The ATS shall be designed to capture and treat a volume equivalent to the runoff from a 10-year, 24-hour storm event in a 72- hour period with a runoff coefficient of 1.0. This is a significant requirement! Must have a filter following coagulation Filter must be monitored by pressure differential 44

45 ATS Instrumentation Turbidity ph Chemicals Flow Volume (also cumulative daily) Data logger 15 mins max interval, store 7 days Auto-shutoff if NELs exceeded 45

46 ATS Effluent Discharge not exceed 20 NTUs for any single sample and 10 NTUs for daily flow weighted average Residual chemical less than 10% MATC 46

47 ATS Monitoring Requirements 47

48 ATS Operator Training Training shall include a minimum of eight hours classroom and 32 hours field training. The course shall cover the following topics: Coagulation Basics Chemistry and physical processes ATS System Design and Operating Principles ATS Control Systems Coagulant Selection Jar testing, dose determination, etc. Aquatic Safety/Toxicity of Coagulants, proper handling and safety Monitoring, Sampling, and Analysis Reporting and Recordkeeping Emergency Response 48

49 ATS Monitoring and Reporting Designated person on site daily at all times during operation with daily inspections Operational Monitoring (15 min intervals) Flow Influent/effluent ph Influent/effluent turbidity Dose rate of all chemicals added 49

50 ATS Reporting Acute toxicity monitoring required Reporting every 30 days using the SMARTS electronic filing Exceed NEL, report to Board w/in 24 hrs 50

51 What is ATS? 2 Approaches Batch Treatment [Pump, Treat, Hold, and Test Before Releasing] Flow-through Treatment [In-line treatment] Source: R. Wright, WashDOT, M.Hromatka, Clearwater Compliance, CASQA

52 52 Source: R. Wright, WashDOT, M.Hromatka, Clearwater Compliance, CASQA 2007

53 Rain Event Action Plan 53

54 Rain Event Action Plan (REAP) Risk Level 2 and 3 only Develop plan 48 hrs prior to a likely rain event (50% chance of rain) REAP must be on site, and implementation starting 24 hours prior to likely rain event Prepared by the QSP Reflect construction stage of site 4 stages 54

55 Stage 1 55

56 Stage 2 56

57 Stage 3 57

58 Stage 4 58

59 Example Site Risk Determination Hillside grading project in Carlsbad: Fictitious site Determine Risk Level: Project sediment risk Receiving water risk Risk determinations drive the requirements for the site They must be done as the first step 59

60 60

61 61

62 Sediment Risk Factor Worksheet A) R Factor 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 l 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 to determine the R factor for the project site. B) K Factor (weighted average, by area, for all site soils) Entry R Factor Value The soil-erodibility factor K represents: (1) susceptibility of soil or surface material to erosion, (2) transportability of the sediment, and (3) the t 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 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 S 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. Refer to GIS Map provided or site-specific specific data (requires submittal of supporting data). C) LS Factor (weighted average, by area, for all slopes) K Factor Value 0.45 The effect of topography on erosion is accounted for by the LS factor, f which combines the effects of a hillslope-length 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 GIS Map provided or LS table located in separate tab of this spreadsheet to determine LS factors. Estimate the weighted LS for the site prior to construction. LS Factor Value 0.01 Watershed Erosion Estimate (=RxKxLS 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 Low 62

63 Determine Site R Factor 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 1,000 locations in the Western U.S. Refer to lewcalculator.cfm 63

64 64

65 Enter R Value A) R Factor 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 to determine the R factor for the project site. R Factor Value

66 USDA Soil Survey

67 Enter K Factor B) K Factor (weighted average, by area, for all site soils) 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 h 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. Refer to GIS Map provided or site-specific specific data (requires submittal of supporting data). K Factor Value

68 Enter LS Value C) LS Factor (weighted average, by area, for all slopes) The effect of topography on erosion is accounted for by the LS factor, f which combines the effects of a hillslope-length 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 GIS Map provided or LS table located in separate tab of this spreadsheet to determine LS factors. Estimate the weighted LS for the site prior to construction. LS Factor Value

69 KLS Map 69

70 Comparison of KLS value vs. K*LS USEPA EMAP Risk Categories, KLS Value Soil Survey, K Factor and Site LS Factor LS determined as 12.2 from topo review, so computed K*LS = 2.68 KLS Value 1.3 K*LS Value 2.6 Since the K*LS value could not be calculated due to unavailable data, the KLS value was used instead. 70

71 Compute Site Sediment Risk Sediment Risk Factor Worksheet A B C Entry A) R Factor 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 to determine the R factor for the project site. B) K Factor (weighted average, by area, for all site soils) R Factor Value 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. Refer to GIS Map provided or sitespecific data (requires submittal of supporting data) K Factor Value C) LS Factor (weighted average, by area, for all slopes) 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 GIS Map provided or LS table located in separate tab of this spreadsheet to determine LS factors. Estimate the weighted LS for the site prior to construction LS Factor Value 12.2 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 High 71

72 72

73 TEMP 73

74 Receiving Water Risk Combined Risk Level Matrix Receiving Water Risk Low Level 1 Sediment Risk Low Medium High Level 2 High Level 2 Level 3 Project Sediment Risk: High 3 Project RW Risk: High 2 Project Combined Risk: Level 3 74

75 How to Prepare 1. New staff training for both design and construction staff 2. Special training on Advanced Treatment Systems is an optional tool (use for difficult sites). ATS operators are required to have certified training on chemical application and toxicity. a. Need inspector(s) ) for each active job. Inspections will ramp up (minimum 48 hours before and 48 hours after event) b. Extensive reporting requirements 75

76 Preparation - more 5. Rain Event Action Plan preparers - QSP (can be the QSD also) 6. Revise Temporary/Construction BMP costs for project estimates 7. Update Guidance: CASQA Handbook now available 8. Possibly longer duration construction period 76

77 Preparation Con t 9. Train staff on use of RUSLE2 (knowledge of soil loss equation and how to quantify before and after BMPs are implemented and for NOT) 10. Time to obtain permission/permits to access receiving water if not accessible for RW monitoring (for Risk 3 sites) 11. Staff time for effluent monitoring and potentially receiving water monitoring at RL 3 sites 12. Time to address public (all reports are posted) 77

78 New Expenses 1. Turbidity meters available to staff (the type that can also measure higher than 1000 NTUs) 2. ph meters available to staff 3. Receiving water monitoring - Risk 3 sites 4. Rain gages (must at RL 3 sites, advised at RL 2) protect against NOVs for events that exceed design storm. 5. Notice of Intent (NOI) fee 6. Advanced Treatment System, if needed ($1.5 Million for a 3 mile project WashDOT example). 7. Bioassessment for some Risk 3 sites 78

79 Other Program Issues/Changes File PRDs for all current sites May want to include some prohibitions in contract (i.e., street washing, chemical storage, washouts) Who is the QSP on RL3 jobs? 79

80 Still Not Rocket Science Where: E=Erosion of the Soil M= Mechanical Disturbance C=Construction Period 80