Drafter
Clerk 10/08/2026
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AN ORDINANCE relating to the production, sale, and use of biosolids and biosolids products; and amending Ordinance 13680, Section 9, and K.C.C. 28.86.090 and Ordinance 13680, Section 18, as amended, and K.C.C. 28.86.180.
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STATEMENT OF FACTS:
1. King County's wastewater treatment facilities have produced and beneficially used class B biosolids as a soil amendment for more than forty years. Class B biosolids have permit limitations on customer use and are typically used for activities such as commercial agriculture and forestry.
2. The King County Code currently limits King County to the production of class B biosolids.
3. King County's biosolids program would greatly benefit from diversifying its product lines and customer base to continue to beneficially use its biosolids.
4. King County's class B markets have limited capacity for expansion and regulatory restrictions on use.
5. King County's class B biosolids are branded as Loop®. Public perception and awareness of King County's biosolids has increased significantly since the brand was launched in 2012. Research has shown there is significant market potential for class A Loop products.
6. The adopted 2021-22 King County biennial budget authorized funding for a biosolids class A compost pilot facility to be constructed at south treatment plant, which has been operational since late 2025. Class A products are retail garden products with no regulatory restrictions on customer use.
7. Direct sale of class A products would allow the county to maximize market potential. Moneys from the sale of class A products would provide an alternative revenue source to help offset operational costs in an environment of increasing sewer rates and affordability challenges.
8. King County is currently undertaking a comprehensive update to the Regional Wastewater Services Plan (RWSP), which will include an update to the biosolids policies in the King County Code. The compost pilot would benefit from interim policy guidance allowing the sale of Class A biosolids, which will provide the wastewater treatment division and the council with important information about the viability of Class A biosolids as a product, and inform the RWSP biosolids policy development. The information will be made available to the council as the council considers new or amended biosolids policies as part of the RWSP update.
9. The compost procurement Ordinance 19552, approved in 2022, specifies county policy for the procurement of compost for use in county projects as required by Washington state law, chapter 43.19A RCW. Ordinance 19552 allows use of compost made from organic material as defined in state law, which includes other sources besides biosolids such as yard and food waste compost, making the current requirement in K.C.C. 28.86.090 specifying use of biosolids compost out of date.
BE IT ORDAINED BY THE COUNCIL OF KING COUNTY:
SECTION 1. Ordinance 13680, Section 9, and K.C.C. 28.86.090 are hereby amended to read as follows:
A. Explanatory material. The biosolids policies are intended to guide the county to ((continue to)) produce and market class A or class B biosolids in accordance with federal, state, and local regulations. The county will also continue to evaluate alternative technologies so as to produce the highest quality marketable biosolids. ((This)) The evaluation would include technologies that produce class A biosolids.
B. Policies.
BP-1: King County shall strive to achieve beneficial use of wastewater solids in accordance with federal, state, and local regulations. A beneficial use can be any use that proves to be environmentally safe, economically sound, and utilizes the advantageous qualities of the material.
BP-2: ((Biosolids-derived products should be used as a soil amendment in landscaping projects funded by King County.
BP-3)) King County shall consider new and innovative technologies for wastewater solids processing, energy recovery, and beneficial uses brought forward by public or private interests. King County shall seek to advance the beneficial use of wastewater solids, effluent, and methane gas through research and demonstration projects.
((BP-4)) BP-3: King County shall seek to maximize program reliability and minimize risk by one or more of the following:
1. maintaining reserve capacity to manage approximately one hundred fifty percent of projected volume of biosolids;
2. considering diverse technologies, end products, and beneficial uses; or
3. pursuing contractual protections including interlocal agreements, where appropriate.
((BP-5)) BP-4: King County shall produce and use biosolids in accordance with federal, state, and local regulations, which may include class A or class B biosolids.
((BP-6)) BP-5: King County shall strive to produce the highest quality biosolids economically and practically achievable and shall continue efforts to reduce trace metals in biosolids consistent with 40 C.F.R. Part 503 pollutant concentration levels (exceptional quality) for individual metals. The county shall continue to provide class B biosolids and also to explore technologies that may enable the county to generate class A biosolids cost-effectively or because they have better marketability. Future decisions about technology, transportation and distribution shall be based on marketability of biosolids products.
((BP-7)) BP-6: When biosolids derived products are distributed outside the wastewater service area, the county shall require that local sponsors using the products secure any permits required by the local government body.
((BP-8)) BP-7: King County shall work cooperatively with statewide organizations on biosolids issues.
((BP-9)) BP-8: King County shall seek to minimize the noise and odor impact associated with processing, transporting and applying of biosolids, consistent with constraints of economic and environmental considerations and giving due regard to neighboring communities.
((BP-10)) BP-9: Where cost-effective, King County shall beneficially use methane produced at the treatment plants for energy and other purposes.
BP-10: King County's biosolids are branded as Loop®. King County may produce class A Loop® biosolids product or products, may distribute them via direct retail or wholesale sales and may receive revenue from the sales. The wastewater treatment division director shall set charges for Loop® services and establish prices for class A Loop® products. Any such charges or prices shall be established or adjusted in writing by the director. In setting charges and prices for Loop® services and class A Loop® products, the director shall consider the following, among other factors: the cost of providing services and products, the demand for services and products, comparable prices for similar services and products, and the administrative costs of collecting the charges.
BP-11: Moneys from the sale of Loop® shall be deposited into the Water Quality Operating Account. Revenue that exceeds biosolids program operating expenses and capital improvements may be spent on other wastewater operating expenses or capital improvements.
BP-12: Consistent with the King County charter and state law restrictions, class A Loop® products and associated Loop® services may be provided free of charge to eligible residents and community gardens within the King County service area to promote the use and sale of class A Loop® products.
SECTION 2. Ordinance 13680, Section 18, as amended, and K.C.C. 28.86.180 are hereby amended to read as follows:
A. The RWSP operational master plan that was adopted by council in December 1999, shall be updated on a regular basis following substantive adopted policy revisions to the RWSP, and shall meet the requirements of K.C.C. chapter 4A.100.
B. The operational master plan shall contain projects related to major program elements and shall further define as necessary the major projects, projected capacity, milestones, projected completion dates, and estimated costs.
1. Treatment capacity.
a. Population and employment growth is projected to require the wastewater system capacity to expand from two hundred forty-eight mgd to three hundred four mgd by 2030. The estimated cost and list of treatment facilities and improvements to achieve this expanded capacity by 2030, shall be included in future RWSP operational master plans, summarized in RWSP annual reports and comprehensive reviews as outlined in K.C.C. 28.86.165.
b. The Brightwater treatment plant at the Route 9 site shall be built with a capacity of thirty-six mgd by 2010 or as soon thereafter as possible to handle wastewater flows from a new north service area as defined in the plan. This plant would provide secondary treatment and would discharge treated effluent to Puget Sound. To facilitate the production of reclaimed water, the possibility of upgrading to tertiary treatment with a freshwater outfall should be investigated before subsequent expansions.
c. Expanding the treatment capacity at the south treatment plant from one hundred fifteen mgd to one hundred thirty-five mgd by 2029. This expansion would handle increased wastewater flows from the southern and eastern portions of the service area. Some or all of the plant capacity could also be upgraded to tertiary treatment, to meet water quality standards or facilitate water reuse, as part of future expansions or in additions to the secondary level of treatment using available land reserves at the plant site.
d. The ((w))West ((p))Point treatment plant will be maintained at its capacity of one hundred thirty-three mgd, primarily to serve the city of Seattle and handle flows from the combined sewers in the area.
2. Conveyance facilities.
a. Conveyance facilities are to be configured, sized, and scheduled to support the treatment plants by conveying wastewater to and treated effluent from the plants. The estimated cost, schedule and list of conveyance facility improvements, shall be included in future RWSP operational master plans, summarized in RWSP annual reports and comprehensive reviews as outlined in K.C.C. 28.86.165.
b. King County will construct additional conveyance improvements (((e.g.)), such as increasing conveyance and pump station capacity and extending conveyance(())), to accommodate increased flows in other parts of the service area to serve population growth in the smaller wastewater service basins and to prevent improper discharges from the sanitary system.
3. I/I control.
a. The I/I control program shall be implemented incrementally and be limited to projects that prove to be most cost effective. The estimated cost, schedule and list of I/I improvement projects, shall be included in future RWSP operational master plans, summarized in RWSP annual reports and comprehensive reviews as outlined in K.C.C. 28.86.165.
b. The goal of the I/I control program is to reduce the expense of conveyance system improvements over time. Every ten years, beginning in 2010, the wastewater treatment division will conduct system monitoring to update hydraulic models and measure the effectiveness of I/I control and reduction in the system.
4. CSOs.
a. The county shall implement CSO control projects consistent with the schedule outlined in the county's long-term CSO control plan as approved in Attachment A to Ordinance 14713 and the Environmental Protection Agency/Washington state Department of Ecology Consent Decree.
b. Consistent with the Environmental Protection Agency/Washington state Department of Ecology Consent Decree, the county may request refinements to the CSO program, including changes to the sequencing of projects, in response to changing conditions, new information and new regulations.
5. Biosolids.
a. King County will continue to produce ((C))class B biosolids using anaerobic digestion at the south and ((w))West ((p))Point treatment plants and to implement the same process at the Brightwater treatment plant until a new technology can be used reliably. If a new technology can be used reliably, King County may produce class A biosolids. The plan also proposes that the county continue to evaluate alternative technologies to reduce the water content of biosolids while preserving their marketability. The primary objective of this evaluation will be to identify alternatives to digesters at the ((w))West ((p))Point treatment plant, a condition of the West Point Settlement Agreement.
b. As part of ongoing planning for its treatment plants, King County will periodically evaluate conventional, alternative and new solids processing technologies using criteria such as product quality (class A or B), marketability, odor and other potential community impacts, impact on sewer rates, reliability of the treatment process, amount of land needed for the treatment facility and the number of truck trips needed to transport the biosolids produced. Based on the results of this evaluation and public comment, the executive ((should recommend)) may implement any one of three biosolids handling scenarios at any ((of)) or all of the treatment plants:
(1) continue using anaerobic digestion;
(2) supplement anaerobic digestion with another treatment technology; or
(3) replace anaerobic digestion with another treatment technology.
c. The estimated cost, schedule, and list of biosolids improvement projects, shall be included in future RWSP operational master plans, summarized in RWSP annual reports and comprehensive reviews as outlined in K.C.C. 28.86.165.
d. The county ((should continue using)) has the authority to recycle biosolids through direct sales or through a public-private partnership approach to recycling biosolids such as using biosolids on working forests in King County to enhance wildlife habitat and generate long-term income from selective timber harvests.
6. Water reuse.
a. The south and ((w))West ((p))Point treatment plants should continue to produce reclaimed water for non-potable uses and explore the production of reclaimed water at new facilities. King County will explore the production of reclaimed water at new facilities and work with water suppliers to plan and implement an accelerated water reuse program that could augment existing water supplies.
b. If a public education and involvement program on water reuse is to be developed and implemented, it shall be coordinated with water conservation education programs. The estimated cost, schedule and list of water reuse projects, shall be included in future RWSP operational master plans, summarized in RWSP annual reports and comprehensive reviews as outlined in K.C.C. 28.86.165.
7. Community treatment systems.
a. Any operations under these policies shall require an operational master plan as described in K.C.C. 4.04.200.C.1. Failure to submit such a plan shall cause the affected capital improvement project to be out of compliance with these polices.
b. In addition to the requirements of K.C.C. 4.04.200.C.1, an operational master plan submitted under these policies shall include:
(1) description of career retention programs that are to be structured in a manner consistent with the King County/((metro))Municipality of Metropolitan Seattle merger, labor law, and King County's labor contracts;
(2) an engineering evaluation that confirms that the selected projects are most cost effective and technically efficacious and consistent with King County growth management policies for the surrounding area; and
(3) explanation of how King County participation in community treatment systems is consistent with other water pollution abatement activities of the department of
natural resources and parks, which currently operates centralized wastewater treatment facilities as contrasted with community treatment systems.