Introduction
King County Stormwater Management Program

King County's Stormwater Management Program (SWMP) describes the actions the County undertakes to comply with the National Pollutant Discharge Elimination System (NPDES) Phase I Municipal Stormwater Permit issued by the Washington State Department of Ecology (Ecology) in 2007 and updated in 2009. Updated annually, the 2012 SWMP’s primary focus is on the compliance activities proposed for 2012.

The NPDES Municipal Stormwater permit affects King County in multiple areas:

• As the local land-use authority for the unincorporated area, King County must have appropriate codes, regulations, and enforcement and education components in place to reduce water-polluting practices and to increase or promote practices that protect water quality.
• As a landowner and property manager, King County must ensure that its own practices meet its own regulatory standards.
• As a local government that strives to protect the environment, King County must conduct a monitoring program that identifies stormwater pollutants and the effectiveness of commonly used best management practices (BMPs), in addition to studying program challenges with the goal of finding more effective, affordable management practices.

As a regional government, King County must coordinate its work with other municipalities, and among the many departments, divisions and sections within county government.

King County has implemented or expanded a number of programs to comply with the permit:

• Mapping– The permit requires King County stormwater drainage and treatment system mapping and requires the county to conduct studies to determine where stormwater goes and how it is treated.
• Coordination – The permit requires King County to work and coordinate with other local governments to find ways to address stormwater problems. King County agencies are also required under the permit to work together to ensure stormwater programs from different agencies are coordinated, and that the required reporting is coordinated by and reported to Ecology from one agency. A written intra-governmental coordination agreement has been written to enact this requirement.
• Public involvement – The SWMP is updated annually, offering the public with an ongoing opportunity to help shape King County’s stormwater management program. King County has developed online videos, Web-based feedback forms, answers to frequently asked questions and posted a draft of the SWMP online. Public involvement remains a crucial part of the program update, and it’s hoped that the convenience of this enhanced online material increases the public’s participation in this effort.
• Controlling runoff from new development, redevelopment and construction sites – The permit requires King County to have updated drainage design and source control rules as well as established standards for staff training and inspections and ensured that the current training meets the needs of the permit. All King County development projects, even those located in other jurisdictions, must comply with the County’s new manual if it is more stringent than that of the jurisdiction in which the development is occurring
• Structural stormwater controls – The permit requires King County report on the stormwater projects that require capital funding, explain why those projects were chosen and detail their effectiveness. More detail is required about the goals of capital projects aimed at reducing the quantity and quality impacts of stormwater from past, present and future land development and the estimated benefits of those projects must be quantified.
• Source control program for existing development – The permit requires that King County identify businesses, and other activities, that contribute pollutants to the stormwater system and implement an inspection, technical support and enforcement program to reduce and eliminate those pollutants. King County has had this program in place and is supported by the Stormwater Pollution Prevention Manual.
• Illicit Connections and Illicit Discharges Detection and Elimination (IC/IDDE) – The permit requires King County to have a spill and illegal dumping response program in place, along with appropriate staff training. The permit also requires King County to have a program that searches for and eliminates connections to the stormwater system that are illegal and discharge non-stormwater to the stormwater system. King County has had stringent water quality codes, staff training standards, and an aggressive inspection and response program addressing these issues, with enforcement timelines.
• Operation and Maintenance Program – King County outlines the maintenance standards for its stormwater system in the King County Surface Water Design Manual which is equivalent to those in the 2005 Ecology Western Washington Manual. In addition to inspecting and maintaining its stormwater system, King County also has an extensive inspection and enforcement program on private stormwater facilities. King County inspects and maintains its own properties to ensure stormwater is not being polluted and has developed stormwater pollution prevention plans (SWPPPs) where required. Staff training standards have been established and training programs implemented.
• Education and Outreach Program – King County has a public education and outreach program that meets permit requirements. Target audiences and topics for stormwater issues have been identified and some of these efforts have been measured to determine the program’s effectiveness. One of the central pieces of this effort has been participation and leadership in the “Puget Sound Starts Here” campaign.

The permit calls for the implementation of a stormwater monitoring program to identify pollutants in stormwater; assess the effectiveness of commonly used control facilities; and measure the effectiveness of one of the permits program elements. Nearly every agency within the King County government is participating in the SWMP.

• The Water and Land Resources Division (WLRD) is charged with coordinating the SWMP and annual reporting. Additionally, the division manages the coordination, public involvement, manual equivalency, structural stormwater control, and public education portions of the SWMP and has a significant role in King County’s source control, IC/IDDE, and operations and maintenance programs. WLRD has developed and implemented a training program.
• Many divisions manage and develop properties and facilities that are not covered under other NPDES permits. These divisions include Wastewater Treatment, Solid Waste, Parks, Roads Maintenance, Transit, the King County International Airport, Facilities Maintenance and the Sheriff’s Office. Drainage facilities on those lands must be mapped, designed and maintained in a manner consistent with permit requirements and King County’s source control BMPs for pollutant-generating activities must be used. Some staff training requirements also apply. SWPPPs must be prepared.
• The Department of Development and Environmental Services is responsible for ensuring the permit requirements are applied to new and re-development. For King County, this action includes not just the Surface Water Design and Stormwater Pollution Prevention manuals, but also related codes, which are applied to new and re-development within the confines of state vesting law.
• Public Health – Seattle & King County’s wastewater program has oversight of onsite sewage systems throughout King County. Corrective actions are taken where there is evidence indicating failing onsite systems are introducing contaminants into stormwater systems. In addition, Public Health regulates and inspects a variety of businesses located throughout the county, and can identify potential illicit discharges or connections to the stormwater system.

The County’s current permit expired Feb. 15, 2012, and has been administratively extended by Ecology to continue to cover the discharges of the County through July 31, 2012. The new permit will become effective Aug. 1, and will cover County activities through July 31, 2013. The content of this permit will be nearly identical to the current permit with few new requirements.

A new permit will become effective Aug. 1, 2013 that will cover the County’s stormwater discharges until 2018. This permit contains new and expanded requirements which will require significant increases in the County’s SWMP. View a copy of the draft stormwater permit (external link, pdf).

The draft permit builds off previous municipal stormwater permits and significantly expands the scope of a number of programs, while introducing several new requirements that contain a new stormwater management philosophy. These significant new requirements will come with many new tasks that will require increases in funding and staff. New sections of this permit will include:

• Total Maximum Daily Loads (TMDL) – Per the Clean Water Act,Ecology is required to identify water bodies that are impaired by pollutants and develop programs to return the waters to beneficial uses, such as fishing and swimming. Central to these recovery plans are TMDLs, which are estimations of how much of a pollutant such as bacteria or nitrogen can be received in a water body and still meet its designated uses. Based on these loading estimates, a plan is written with requirements for the pollutant contributors to enact which are developed by Ecology and approved by the Environmental Protection Agency to reduce loading of the pollutant. King County has requirements in this permit for four TMDLs. The permit calls on the County to enact stormwater management actions within the basins of these four TMDL-listed waterbodies.
  
• Low Impact Development (LID) is an approach to stormwater management that focuses on controlling stormwater at its source using systems that mimic natural processes like infiltration, plant uptake, and small scale storage and release. LID BMPs include, but are not limited to, bio-retention/rain gardens, permeable pavements, roof downspout controls, dispersion, soil quality and depth, vegetated roofs, minimum excavation foundations and water re-use.
  
  This new permit requires LID be used wherever feasible for stormwater management during site development or redevelopment. This is paradigm shift will place more stormwater treatment and flow control from impervious surfaces on decentralized, privately owned, and maintained systems instead of the current system in which stormwater is routed to centralized stormwater control facilities maintained by local governments.
  
• The permit proposes participation in a collaborative, regional approach to stormwater monitoring as the preferred approach in lieu of individually conducted monitoring activities. This shared effort will help to standardize the collection of data as well as reduce costs for participating jurisdictions.

For questions about the King County Stormwater Management Program, please contact Giles Pettifor, Project/Program Manager, Stormwater Services Section.