Storm Water Blue Ribbon Panel Recommendations to the California State Water Resources Control Board The Feasibility of Numeric Effluent Limits Applicable to Discharges of Storm Water Associated with Municipal, Industrial and Construction Activities Panels Report and the Proposed Construction Permit Eric Strecker Geosyntec Consultants

Blue Ribbon Panelists Brian Currier, PE Research Engineer, Office of Water Programs, California State University Sacramento, Sacramento, California Gary Minton, Ph.D, PE Resource Planning Associates, Seattle, Washington Robert Pitt, Ph.D., PE Cudworth Professor of Urban Water Systems, Dept. of Civil, Construction, and Environmental Engineering, University of Alabama, Tuscaloosa Larry A. Roesner, Ph.D., PE. Colorado State University, Fort Collins, Colorado Ken Schiff Deputy Director, Southern California Coastal Water Research Project, Westminster, California Mike Stenstrom, Ph.D., PE Dept. of Civil and Environmental Engineering, University of California at Los Angeles, Los Angeles, California Eric Strassler Senior Policy Analyst, Office of Water, US USEPA Washington, DC Eric Strecker, PE Principal, GeoSyntec Consultants, Portland, Oregon 2

Panel of experts was asked to consider the following: Is it technically feasible to establish numeric effluent limitations, or some other quantifiable limit, for inclusion in storm water permits? Is it technically feasible to establish numeric effluent limitations, or some other quantifiable limit, for inclusion in storm water permits? How would such limitations or criteria be established, and what information and data would be required? How would such limitations or criteria be established, and what information and data would be required? 3

Panel of experts was asked to consider the following: The answers should address industrial general permits, construction general permits, and area-wide municipal permits. The answers should address industrial general permits, construction general permits, and area-wide municipal permits. The answers should also address both technology-based limitations or criteria and water quality-based limitations or criteria. The answers should also address both technology-based limitations or criteria and water quality-based limitations or criteria. In evaluating establishment of any objective criteria, the panel should address all of the following: In evaluating establishment of any objective criteria, the panel should address all of the following: (1) The ability of the State Water Board to establish appropriate objective limitations or criteria; (1) The ability of the State Water Board to establish appropriate objective limitations or criteria; (2) how compliance determinations would be made; (2) how compliance determinations would be made; (3) the ability of dischargers and inspectors to monitor for compliance; and (3) the ability of dischargers and inspectors to monitor for compliance; and (4) the technical and financial ability of dischargers to comply with the limitations or criteria. (4) the technical and financial ability of dischargers to comply with the limitations or criteria. 4

What we were not asked to do: Recommend whether or not effluent limits should be adopted Recommend whether or not effluent limits should be adopted Specify which technology(ies) should or should not be employed Specify which technology(ies) should or should not be employed Develop details regarding how to implement our recommendations Develop details regarding how to implement our recommendations 5

Construction Findings Traditional Erosion and Sediment Controls on a site basis are variable in performance Traditional Erosion and Sediment Controls on a site basis are variable in performance Site to site variability in TSS/Turb on natural sites is also quite high Site to site variability in TSS/Turb on natural sites is also quite high Active treatment systems, including those that use Polymers and sedimentation (and electro-flocculation) have been demonstrated to achieve low turbidity consistently for a wide range of storms Active treatment systems, including those that use Polymers and sedimentation (and electro-flocculation) have been demonstrated to achieve low turbidity consistently for a wide range of storms Other pollutants have not received enough emphasis Other pollutants have not received enough emphasis Permits do not require training or certification Permits do not require training or certification The quality of stormwater discharges from construction sites that effectively employ BMPs likely varies due to site conditions such as climate, soil, and topography The quality of stormwater discharges from construction sites that effectively employ BMPs likely varies due to site conditions such as climate, soil, and topography The States of Oregon and Washington have recently adopted similar concepts to Action Levels The States of Oregon and Washington have recently adopted similar concepts to Action Levels 6

Panels Construction Conclusions It is the consensus of the Panel that active treatment technologies make Numeric Limits technically feasible for pollutants commonly associated with stormwater discharges from construction sites (e.g. TSS and turbidity) for larger construction sites. It is the consensus of the Panel that active treatment technologies make Numeric Limits technically feasible for pollutants commonly associated with stormwater discharges from construction sites (e.g. TSS and turbidity) for larger construction sites. While the Panel concludes that Numeric Limits or Action Levels are technically feasible, the Panel has several [13 of them] reservations and concerns (regarding the use of active treatment systems and numerical effluent limits) While the Panel concludes that Numeric Limits or Action Levels are technically feasible, the Panel has several [13 of them] reservations and concerns (regarding the use of active treatment systems and numerical effluent limits) 7

Construction However, setting an upset (Action) value is possible using: However, setting an upset (Action) value is possible using: Consensus value (e.g. 100 ppb dissolved Cu is too much) Consensus value (e.g. 100 ppb dissolved Cu is too much) Percentile of observed values Percentile of observed values Statistically-based population parameters of observed values Statistically-based population parameters of observed values …identify the [statistically derived] point at which managers feel concentrations are significantly beyond the norm 8

Percentile of observed values 95% Value 95% Value 9

Statistically-based population parameters of observed values e.g. two standard deviations above the mean concentration e.g. two standard deviations above the mean concentration 10

Include Exceedance Storm or Intensity Concept that BMPs sizing is important Concept that BMPs sizing is important Agencies [or others] should not be accountable for water quality in volumes or flows above a set design level Agencies [or others] should not be accountable for water quality in volumes or flows above a set design level 11

Reservations and Concerns Consideration should be given to the seasonality of applying Numerical Limits. (dont de-incentive grading timing). Consideration should be given to the seasonality of applying Numerical Limits. (dont de-incentive grading timing). Apply to construction sites with exposed graded areas, not ones that have been stabilized Apply to construction sites with exposed graded areas, not ones that have been stabilized Where Numeric Limits are not feasible employ Action Levels for sites where only traditional erosion and sediment controls are applied or construction sites that are considered stabilized for the runoff season. Where Numeric Limits are not feasible employ Action Levels for sites where only traditional erosion and sediment controls are applied or construction sites that are considered stabilized for the runoff season. An Action Level indicates a failure of BMPs (within some storm size limits). An Action Level indicates a failure of BMPs (within some storm size limits). 12

Reservations and Concerns The Board should consider Numeric Limits or Action Levels for other pollutants of relevance to construction sites, but in particular pH. The Board should consider Numeric Limits or Action Levels for other pollutants of relevance to construction sites, but in particular pH. The Board should consider the phased implementation of Numeric Limits and Action Levels, commensurate with the capacity of the dischargers and support industry to respond. The Board should consider the phased implementation of Numeric Limits and Action Levels, commensurate with the capacity of the dischargers and support industry to respond. The Panel recommends that a Numeric Limit or Action Level should be compared to the average discharge concentration. The Panel recommends that a Numeric Limit or Action Level should be compared to the average discharge concentration. 13

Reservations and Concerns The Board should set different Action Levels that consider the sites climate region, soil condition, and slopes, and natural background conditions (e.g. vegetative cover) as appropriate and as data is available. The Board should set different Action Levels that consider the sites climate region, soil condition, and slopes, and natural background conditions (e.g. vegetative cover) as appropriate and as data is available. The Board should consider whether the Numeric Limits or Action Levels should differ between receiving waters that are water quality limited with respect to turbidity, sediment or other pollutants associated with construction, from those water bodies that are not water quality limited. The Board should consider whether the Numeric Limits or Action Levels should differ between receiving waters that are water quality limited with respect to turbidity, sediment or other pollutants associated with construction, from those water bodies that are not water quality limited. 14

Reservations and Concerns The Panel recommends that Numeric Limits and Action Levels not apply to storms of unusual event size and/or pattern (e.g. flood events). The determination of Water Quality Capture Volume should consider the differing climate regions to specify these events. The Panel recommends that Numeric Limits and Action Levels not apply to storms of unusual event size and/or pattern (e.g. flood events). The determination of Water Quality Capture Volume should consider the differing climate regions to specify these events. The Board should set Numeric Limits and Action Levels to encourage loading reductions as appropriate as opposed to only numeric concentrations. The Board should set Numeric Limits and Action Levels to encourage loading reductions as appropriate as opposed to only numeric concentrations. phased construction (e.g. limited exposed soil areas or their duration), infiltration, and spraying captured runoff in vegetated areas as means to reduce loading. phased construction (e.g. limited exposed soil areas or their duration), infiltration, and spraying captured runoff in vegetated areas as means to reduce loading. 15

Reservations and Concerns The Panel is concerned that the monitoring of discharges to meet either the Action Levels or Numeric Limits may be costly. The Panel recommends that the Board consider this aspect. The Panel is concerned that the monitoring of discharges to meet either the Action Levels or Numeric Limits may be costly. The Panel recommends that the Board consider this aspect. 16

Reservations and Concerns (Industrial) The Panel recognizes the inadequacy of current monitoring data sets and recommends improved monitoring to collect data useful for establishing Numeric Limits and Action Levels. The Panel recognizes the inadequacy of current monitoring data sets and recommends improved monitoring to collect data useful for establishing Numeric Limits and Action Levels. Insofar as possible, the Panel prefers the use of California data in setting Numeric Limits and Action Levels. Insofar as possible, the Panel prefers the use of California data in setting Numeric Limits and Action Levels. 17

Summary Blue Ribbon Panel vs. Proposed Permit Many of our recommendations have been implemented in the permit Many of our recommendations have been implemented in the permit Differences: Differences: Using monitoring data or consensus approach to set NALs that are significantly beyond the norm Using monitoring data or consensus approach to set NALs that are significantly beyond the norm Including a compliance assessment (design) storm as recommended for NALs and NELs (i.e. should not be responsible during flood events for NALs/NELs) Including a compliance assessment (design) storm as recommended for NALs and NELs (i.e. should not be responsible during flood events for NALs/NELs) With exception of the use of ATS, panel found NELs not technically feasible at this time for construction sites With exception of the use of ATS, panel found NELs not technically feasible at this time for construction sites We recommended the need for more comprehensive and planned monitoring (in Industrial section, but applicable to all) We recommended the need for more comprehensive and planned monitoring (in Industrial section, but applicable to all) Could reconvene Panel to address additional technical questions, new information and potential approaches Could reconvene Panel to address additional technical questions, new information and potential approaches 18