September 13, 2005
SUBJECT: Introduction of Ordinance Amending Chapter 12.60 "Storm Water Management" of the Sunnyvale Municipal Code, to Add Hydromodification Plan Requirements and Amend Project Size for Applicability of Treatment Requirements
REPORT IN BRIEF
In August 2003, Council adopted Chapter 12.60 "Storm Water Management" in response to new Storm Water Discharge Permit Requirements. It was known at that time that the new treatment requirements would initially be applicable to projects of an acre or more in size, and would be applied to smaller projects at a later date, and in addition, that new requirements for flow control of runoff to creeks, or the “Hydromodification Management Plan” were also to be implemented. This amendment to Chapter 12.60 now defines the smaller size, or “Group 2” projects to which the storm water discharge requirements are to apply. The amendment also adds the new Hydromodification Management Plan requirements for flow control, and provides for the exemptions allowed in the permit. Adoption of these amendments will allow for compliance with the City’s Municipal Separate Storm Sewer System National Pollutant Discharge Elimination System (NPDES) Permit requirements, pursuant to the Federal Clean Water Act.
Staff recommends adoption of the amendments to Chapter 12.60 of the Sunnyvale Municipal Code.
BACKGROUND
The City’s current NPDES permit to discharge storm water into local creeks and South San Francisco Bay permit was issued in February 2001. In October 2001, the permit was amended to include a specific provision, C.3 - New and Redevelopment Performance Standards. C.3 created two categories of projects to which certain requirements apply, based on size. Group 1 applies to projects of one acre or more of new or replaced impervious surface (surface that won’t allow storm water to infiltrate but instead allows it only to run off), and Group 2 applies to smaller projects, or those adding or replacing 10,000 square feet or more of impervious surface. Implementation of Group 1 was required to begin by October 15, 2003, and implementation of Group 2 (as amended by the Regional Water Quality Control Board on July 20, 2005) is required to begin by October 20, 2005.
In response to the requirements for Group 1 and to allow for implementation
and compliance with the permit conditions, Council adopted Chapter 12.60 in August 2003. In the Report to Council dated August 19, 2003, staff indicated that they would return to Council to address the Group 2 project requirements and update Chapter 12.60 after receiving approval of the flow requirements and any revisions to the Group 2 definition from the Regional Water Quality Control Board. Such approval was received on July 20, 2005.
Staff is now requesting that Council approve amendments to Chapter 12.60 to provide the required authority for implementation of the Group 2 requirements. The proposed changes are as follows:
· Chapter 12.60 - The size threshold for applicability of the requirements for storm water treatment design requirements for new and redevelopment projects is reduced from one acre to 10,000 square feet of new or replaced impervious surface.
· Reference to Group 1 and Group 2 have been eliminated to reflect that the new, smaller Group 2 size for applicability supercedes the previous Group 1 size. Reference now is simply to the new 10,000 square foot applicability.
· Section 12.60.160 is added to incorporate the Hydromodification Management Plan requirements for flow control.
· An exemption is provided for the construction of projects consisting of one single-family home, provided that appropriate pollutant source control and design measures are included to minimize storm water discharges from the site.
· The new requirements will be applicable to projects for which applications are submitted and deemed to be complete by the Director of Community Development on or after October 20, 2005. Public Works projects for which funding has been committed and construction scheduled by October 20, 2005, will also be required to implement the new requirements.
EXISTING POLICY
Chapter 12.60.120 requires specific storm water treatment design requirements for new and redevelopment projects that add or replace one acre or more of impervious surface implement storm water best management practices to the maximum extent practicable to reduce storm water pollution. These have been required for new and redevelopment projects approved since October 15, 2003.
Chapter 12.60.160: Group 2 projects has been reserved, pending the approval of the final definition of Group 2 projects by the Regional Water Quality Control Board. In order to comply with the date previously set in the permit, public and private projects have been required, by policy, since April 15, 2005, to implement the Group 2 requirements. This policy was necessary to ensure compliance with the permit while negotiations proceeded with the Regional Water Quality Control Board for the specific requirements for Group 2 projects.
DISCUSSION
Chapter 12.60.160 allows staff to implement the City’s NPDES Storm Water Discharge Permit Provision C.3 for Group 1 projects. The proposed changes will allow the storm water treatment requirements to be applied to the category of smaller projects defined in the permit as Group 2, and will allow implementation of the Hydromodification Management Plan requirements. For the sake of clarity, the distinction of “Group 1” and “Group 2” have been eliminated from the Code, and reference is now simply to the 10,000 square foot size applicability.
Impact to Developers: A storm water management plan describing how a proposed project will meet the requirements of the Chapter 12.60 is currently required from applicants wishing to obtain a development permit from the City for projects that add or replace one acre of impervious area. The project size will now be reduced to address those projects that add or replace 10,000 square feet of impervious area. This will increase the number of projects that must prepare storm water management plans to address post-construction storm water treatment and the operations and management of best management practices to prevent storm water pollution. In addition, for projects that create or replace one acre or more of new impervious surface and drain to areas not exempted, Hydromodification Management Plan flow control requirements will apply. Specifics of applicability are included in the ordinance.
Single family residence projects that are not a part of a larger subdivision development are exempt from storm water treatment and flow control requirements, but are required to include appropriate source control and site design measures.
Impact to the City: The City’s own municipal projects that add or replace 10,000 square feet of impervious surface will need to prepare a storm water management plan to include best management practices that treat storm water to the maximum extent practicable and include post-construction operations and management plans. Flow control requirements of the Hydromodification Management Plan would apply to City projects if the City were to implement a project in the applicable areas (where no City ownership currently exists).
Failure to comply with the requirements of the City’s NPDES Storm Water Discharge permit would constitute a violation of the California Water Code and regulations, making the City subject to enforcement actions with the potential for administrative civil liability, civil monetary penalties, and citizen suits.
ENVIRONMENTAL REVIEW
Adoption of this ordinance is exempt from CEQA review because it is implementing requirements mandated by a regulatory agency for the protection of the environment. Individual development projects covered by the ordinance will be subject to applicable CEQA review at the time they are processed.
FISCAL IMPACT
Fiscal impacts to City capital projects may be as much as 2% of project costs. Under Chapter 12.60.280, if projected costs of required on-site measures exceed 2% of total project costs, then the project may qualify under the impracticability criteria and the City may grant eligibility for alternative compliance under Chapter 12.60.300.
Fiscal impacts to private projects would be similar.
Conclusion
Approving the amendment to include the applicability of treatment measures for smaller projects, in Section 12.60.120, and the addition of Section 12.60.160 – “Hydromodification Management Plan (HMP) Requirements; Applicability” for flow control will allow the City to remain in compliance with the provisions of its NPDES discharge permit.
PUBLIC CONTACT
Public contact was made through posting of the Council agenda on the City's official notice bulletin board, posting of the agenda and report on the City's web page, publication of the Council agenda in the San Jose Mercury News, and the availability of the report in the Library and the City Clerk's Office.
A flyer that describes the impervious area size threshold changes and the requirements for those projects will be available at the One Stop Permit Center for new and redevelopment project applicants
ALTERNATIVES
1. Adopt an Ordinance amending Chapter 12.60 and adding Section 12.60.160 to the Sunnyvale Municipal Code to define the applicability of treatment requirements to smaller size projects and to add the Hydromodification Management Plan requirements.
2. Request additional information and modified language for the proposed ordinance.
3. Do not approve any changes to the Sunnyvale Municipal Code. Not adopting changes to the Code will result in the City not being in compliance with the requirements of its NPDES Storm Water Discharge permit.
RECOMMENDATION
Staff recommends Alternative #1: Adopt an Ordinance amending Chapter 12.60 and adding Section 12.60.160 to the Sunnyvale Municipal Code to define the applicability of treatment requirements to smaller size projects and to add the Hydromodification Management Plan requirements.
Adoption of these amendments will allow for compliance with the City’s Municipal Separate Storm Sewer System National Pollutant Discharge Elimination System (NPDES) Permit requirements, pursuant to the Federal Clean Water Act.
Reviewed by:
Marvin A. Rose, Director of Public Works
Prepared by: Lorrie B. Gervin, Environmental Division Manager
Approved by:
Amy Chan
City Manager
Attachments
A. Proposed Ordinance Amending Sunnyvale Municipal Code (.pdf)