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Item 16 Staff Report Proposed Changes to Performance Standards in the Town's NPDES Storm Water Discharge Permit and the Implications to the TownCOUNCIL AGENDA REPORT DATE: June 13, 2001 TO: MAYOR AND TOWN COUNCIL FROM: TOWN MANAGE SUBJECT: MEETING DATE: 6/18/01 ITEM NO. w' PROPOSED CHANGES TO PERFORMANCE STANDARDS IN THE TOWN'S NPDES STORM WATER DISCHARGE PERMIT AND THE IMPLICATIONS TO THE TOWN RECOMMENDATION: Support sixty day time extension for public comment on proposed regulations. DISCUSSION: As of June 6`h, the Santa Clara Valley Urban Runoff Pollution Prevention Program's legal counsel has sent a letter to the Regional Water Quality Control Board requesting a 60-day extension of the public comment period. Regional Board staff is discussing the request with their managers and said they would let us know their decision in the next few days. Until we hear otherwise, we should assume that comments on the proposed changes are due on June 186, which is the date of this meeting. Because of the significant implications of the new provisions, staff will prepare comments that will be sent to Council as a Desk Item. If the 60 day extension is granted, any comments from the Council could be added to staff's comments. To date, staff have only made verbal comments to the Sanitation District about potential concerns with respect to potential impacts on workload and on the cost of development. If the 60-day extension of the public comment period is granted, the staffs of the Community Development and Parks & Public Works Departments will have an opportunity to more fully assess the additional costs and workload associated with these measures, identify potential funding sources, and begin to assess the changes needed to implement these new requirements. PREPARED BY: LES WHIT Interim Director of Parks and u is orks Reviewed by: Ok. Attorney Clerk 4" Finance Community Development Revisers• 6/1 01 R•119 AM Reformatted: 5/30/01 N:1B&E\CNCLRPTS\npdes.wpd PAGE 2 MAYOR AND TOWN COUNCIL SUBJECT: PROPOSED CHANGES TO PERFORMANCE STANDARDS IN THE TOWN'S NPDES STORM WATER DISCHARGE PERMIT AND THE IMPLICATIONS TO THE TOWN June 13, 2001 DISCUSSION: We could further assess the position of other local governments, primarily the other "Co-permittees," and determine whether the Town should actively seek changes to the proposed regulations that will be considered by the Regional Board. Attached is an overview of the proposed new regulations and the impact on the Town. ENVIRONMENTAL ASSESSMENT: This is not a project defined under CEQA, and no further action is required. FISCAL IMPACT: As yet undetermined to the Town are additional costs to implement, oversee, and report on these programs. Attachments: Summary of Key Implications for Local Government, prepared by the Santa Clara Valley Urban Runoff Pollution Prevention Program Tris`n Duarte - key implications summ, loc Page 1 SANTA CLARA VALLEY URBAN RUNOFF POLLUTION PREVENTION PROGRAM DRAFT PERMIT LANGUAGE FOR CONTROL OF STORMWATER POLLUTION FROM NEW DEVELOPMENT AND RE -DEVELOPMENT SUMMARY OF KEY IMPLICATIONS FOR LOCAL GOVERNMENTS BACKGROUND • The Santa Clara Valley Urban Runoff Pollution Prevention Program is a consortium of 13 cities and towns in Santa Clara County, as well as the County and the Santa Clara Valley Water District, that share a common permit to discharge stormwater to San Francisco Bay. These entities are referred to as "Co-permittees". • The Program's current permit requires mitigation of stormwater quality impacts of new and redevelopment to the "maximum extent practicable" (MEP). MEP is defined in the Program's Performance Standards for Planning Procedures and Construction Inspection, which represent the level of implementation required by each Co- permittee. • Currently, Co-permittees are requiring developers of projects with significant stormwater pollution potential (as defined in environmental reviews) to mitigate stormwater quality impacts using site planning and design techniques and/or permanent stormwater treatment control measures. These requirements apply to private and public projects. Planning or building department staff use internal guidance and professional judgment to determine which projects have significant impacts, and which types of stormwater controls are appropriate. PROPOSED PERMIT REVISIONS The Regional Water Quality Control Board has released a Tentative Order with proposed revisions to the requirements for new and redevelopment projects, including: • Standards for sizing stormwater treatment controls so that 80 to 85% of the stormwater runoff from development sites each year gets treated, either through infiltration into surface soils, detention, or filtration in a treatment device. • Limits on increases in peak stormwater discharges from new or redevelopment sites that may increase erosion in creeks. The interim standard is that post -development peak stormwater discharges may not exceed pre -development peak discharges for storm sizes up to a 10-year recurrence interval (i.e., the stormwater discharge that will occur about once in 10 years).. Co-permittees are allowed to propose alternative creek -specific limitations using information from watershed assessments. • Requirements for operation and maintenance of stormwater controls. Municipalities will need to: 1) require property owners/developers and successive owners to accept responsibility for maintenance; and 2) verify proper maintenance through a local agency inspection program. • Definition of a minimum project size for which the design standards, peak flow limitations, and maintenance requirements apply. Initially, the standards will apply to Trisn Duarte - key implications summ, loc Page 2 all projects that create one acre (43,560 sq. ft.) or more of impervious surface (i.e, surface that does not allow water to infiltrate and thus creates runoff). After July 2003, the minimum project size will be reduced to include all projects that create 5,000 sq. ft. or more of impervious surface, unless Co-permittees propose an alternative minimum size definition that encompasses 80% of new impervious surface creation in a given year. • Schedule for implementation. Co-permittees will have 1 year to modify development approval processes and begin the maintenance verification program; 1 '/ years to develop an alternative minimum size proposal; 2 years to submit alternative creek - specific peak flow limitations and draft revised local design standards; and 3 years to fully implement revised design standards and guidance. IMPLICATIONS TO MUNICIPAL PROGRAMS • There will be significant costs to municipalities to develop procedures for, conduct training on, implement, oversee, and report on these programs. • After July 2003, municipalities may need to conduct stormwater reviews of smaller, ministerial projects that currently only require a building permit, resulting in increased staffing requirements and permit delays. • If infiltration is not practical on a development site, treatment measures such as detention ponds will likely be needed, which may create maintenance, vector control, and public safety problems. • The cost of stormwater controls and the land needed to accommodate them may drive up the cost of housing, especially in high density developments, and may have a disproportionate impact on low-income and affordable housing. • The requirements may impact the ability of a City to redevelop within downtown areas and drive more development to outlying areas. ACTION Comments on the proposed revisions are due to the Regional Board by 5:00 p.m. on June 18, 2001. The revised permit will be heard by and possibly adopted by the Regional Board at its July 18, 2001 meeting. For more information on the permit contact Jan O'Hara at the RWQCB (510) 622-5681.