March 2026

View this project notice in Spanish: Leer este correo electrónico en Español.

Septic or sewer: Your questions matter. Updated April dates for library chats.

We have new dates for our April library chats. These chats let you meet with our team, learn about the project, and tell us what matters to you.

Thanks to everyone who joined us in March at the Covington and Black Diamond libraries! We are so thankful for the opportunity to meet and learn from you!

April library chat dates (updated)

We changed our April dates at both libraries. Here are the new times and locations:  

• Friday, April 17
  • Location: Covington Library
  • Time: 3 – 6 p.m.
• Saturday, April 25
  • Location: Black Diamond Library
  • Time: 12 – 4 p.m.
    

Septic users: Your top questions answered in March

Many people in March told us they use septic systems at their homes. We want to hear from you too!

Here are the top questions we heard from septic users and our responses:

Will septic users be required to connect to sewer as part of this project?

No. The pipe we are upgrading is a regional sewer pipe. Homes and businesses cannot connect directly to it.

Local sewer agencies manage the smaller pipes near homes and businesses. They also decide where people can connect to new sewer service. King County’s role is to move and treat the wastewater that local agencies send to us.

Why should septic users care about this project?

Even if you are not connected to sewer, our project team still wants to hear from you! As project neighbors, we want to talk to you because:

• Construction will affect local roads. Expect traffic delays. The existing sewer pipe is located under streets in your area. We must work in the road to upgrade the pipe.
• Email updates will help you stay informed. You can learn about traffic impacts, share feedback, and help us plan ways to reduce disruptions.
• King County can help you dispose of septic waste! We run a 24/7 septage disposal and treatment facility at the South Treatment Plant in Renton. The facility accepts domestic and commercial septage waste with proper permits. Domestic septage is wastewater from residential septic tanks. To learn more about this King County service and domestic septage hauling, visit our Septage Disposal website.

Do septic users pay King County’s wholesale monthly sewer rate?

No. People who use septic systems do not pay King County’s wholesale monthly sewer rate.

Can’t make it to a chat? Contact our team!

We are happy to meet you another time or visit your next community event. We can share project updates and answer your questions. 

For more information, contact Annie Plumley at 206-263-3203 or BDSewerUpgrade@kingcounty.gov

ALTERNATE FORMATS AVAILABLE – 206-477-5371 OR TTY RELAY: 711 

About the Project: 

The City of Black Diamond built the Black Diamond Trunk sewer pipe in 1992 with help from King County. Now the pipe is almost full. King County plans to upgrade it to serve the growing community. We may repair the pipe, expand it, or add new pipes. The Black Diamond Trunk Sewer carries wastewater from the City of Black Diamond. The pipe runs north of the city between Black Diamond and Covington.

Los servicios de interpretación y traducción están disponibles para usted sin costo alguno. Si los necesita, comuníquese con Annie Plumley, BDSewerUpgrade@kingcounty.gov, (206) 263-3203. 

免費為您提供口譯和筆譯服務。如果您需要這些服 務，請聯 絡 BDSewerUpgrade@kingcounty.gov

免费为您提供口译和笔译服务。如果您需要这些服 务，请联络 BDSewerUpgrade@kingcounty.gov

Dịch vụ thông dịch và biên dịch được cung cấp miễn phí cho quý vị. Nếu quý vị cần những dịch vụ này, xin vui lòng liên hệ với BDSewerUpgrade@kingcounty.gov

आपके लिए दुभाषिया और अनुवाद सेवाएं बिना किसी शुल्क के उपलब्ध हैं। यदि आपको इनकी आवश्यकता हो, तो कृपया संपर्क करें BDSewerUpgrade@kingcounty.gov

Вам доступні безкоштовні послуги усного та письмового перекладу. Якщо вони вам потрібні, зверніться за адресою електронної пошти BDSewerUpgrade@kingcounty.gov

Вам доступны бесплатные услуги устного и письменного перевода. Если они вам необходимы, обратитесь по адресу электронной почты BDSewerUpgrade@kingcounty.gov

ਦੁਭਾਸ਼ੀਆ ਅਤੇ ਅਨੁਵਾਦ ਸੇਵਾਵਾਂ ਤੁਹਾਡੇ ਲਈ ਮੁਫ਼ਤ ਵਿੱਚ ਉਪਲਬਧ ਹਨ। ਜੇਕਰ ਤੁਹਾਨੂੰ ਇਹਨਾਂ ਦੀ ਲੋੜ ਹੈ ਤਾਂ ਕਿਰਪਾ ਕਰਕੇ ਸੰਪਰਕ ਕਰੋ BDSewerUpgrade@kingcounty.gov