King County Industrial Waste Newsletter - Spring 2023

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King County Industrial Waste Program Newsletter - Spring 2023

Industrial Waste Pretreatment Annual Report

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The King County Industrial Waste Program (KCIW) regulates approximately 650 commercial and industrial customers that discharge wastewater into King County’s regional wastewater system. We are a delegated industrial waste pretreatment program and are required to meet the National Pollutant Discharge Elimination System (NPDES) permit requirements for King County's Wastewater Treatment Division’s treatment plants. One of these requirements is the submission of an Annual Pretreatment Report to the Washington Department of Ecology.

Read the Industrial Pretreatment Annual Report to learn more about KCIW’s achievements in the areas of operations, special projects and activities, and public outreach.

Clean Water Awards – The Envelope Please...

Each spring, KCIW recognizes facilities that have done an excellent job maintaining permit compliance and preventing pollution during the previous calendar year. Companies with excellent compliance help protect WTD’s workers and sewer and treatment plants as well as the environment.

Congratulations to the Commitment to Compliance winners: Port of Seattle, Primus International, and Boeing Electronics Center! 

Find out who won Gold,and Silver awards.

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Apply for an EnvirOvation award!

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Tell us about your innovative, sustainable, and/or cost saving project. The EnvirOvation Award application deadline is Nov. 1st. We encourage all permitted facilities to apply for our annual EnvirOvation Award for excellence in pretreatment. Learn about the awards criteria and download an application: KCIW rewards and recognition program.

Decommissioning our fax line

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KCIW will soon be disconnecting our fax line. If you have forms or other information to send us, please only send it via email to our email address:

As an absolute last resort, some items that are not time sensitive can be physically mailed. This is not our preference and we do not monitor our physical mailbox on a routine basis. Our physical mailing address is: King County Industrial Waste Program | 201 S Jackson St | Mail Stop: KSC-NR-5513 | Seattle, WA 98104

Companies that violate clean water rules receive penalties - 2022 violators

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King County is legally required to report on companies who do not comply with their permit or regulations. KCIW publishes a violators advertisement once a year in the spring for violations and enforcement actions that have occurred since the previous publication date. View the latest enforcement ad, which was published in the Seattle Times in early May.

How to Avoid Penalties

Late submissions are a frequent and preventable reason for violations and fines. Plan ahead. File your applications and reports on time.

Did you know…?

  • Your permit shows your specific deadlines.
  • You can contact a King County Industrial Waste Investigator and ask for an extension to avoid being late.
  • You can send your reports electronically to KCIW by emailing

Flow proportional sampling can be more accurate, but first make sure your equipment is compatible with ours

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If you have received formal authorization from KCIW to discharge your wastewater to the sanitary sewer, you may be expected to monitor your wastewater discharges for pollutants of concern. Many companies choose to use autosamplers for this monitoring. These samplers can collect wastewater samples in two ways: either on regular time intervals, or on intervals based on the volume of water being discharged – known as flow-proportional sampling.

Companies that discharge multiple batches each day, do not operate 24/7, and/or those that have a variable rate of effluent can get more accurate samples by using flow proportional sampling. Collecting flow-proportional samples is one of the best ways to get representative composite samples using an autosampler in these cases.

Flow proportional sampling may also be how KCIW collects representative composite samples from your discharge. To do any flow proportional monitoring, a 4-20 mA interface cable must be attached to your flow meter. This interface cable will convert the output signal from the flow meter in proportion to the flow and send a pulse to the autosampler. Each signal pulse is sent after a set number of gallons is discharged. The autosampler will collect an aliquot (sample) after a designated number of pulses. Most meters will allow you to set the value for gallons of discharge per pulse. For ease of calculation, 100 gallons of discharge per pulse sent works well for many facilities.

Before you purchase or install an effluent flow meter, get approval on the model from KCIW. Your flow meter must be compatible with King County’s monitoring equipment.

Some important things we look for in a company’s flow meter:

  • The ability to connect a flow proportional cable to the unit.
  • The ability of the flow meter to measure the anticipated minimum and maximum flow rates.
  • The ability of the flow meter to generate a 4 to 20 mA signal for use with external devices (such as an autosampler). The range of the 4 to 20 mA signal should reflect the minimum and maximum flow rate from the flow meter.

KCIW will supply the flow proportional cable and use this connection when we collect composite samples with the autosampler. Please speak with a member of the sampling team or your assigned investigator to have a cable delivered and/or installed.


Image credit: Teledyne ISCO

Getting to the source of pollution… and doing something about it

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There are many reasons to move to King County – culture, recreation, natural beauty, and jobs, to name a few – and more and more people are moving here each year. But more people means more pollution from cars, trash, pet waste, pesticides from yards, business operations, and emissions. And all of this can impact water quality.

In the 1950s, King County (formally Metro) heard the cry of its residents to stop sewage from flowing into its waterbodies. Since then, we have greatly changed the way we handle wastewater (that contains both stormwater and sewage). Because of these efforts, water and sediment quality in the region is much healthier than it was a generation ago. But there are many ways pollution can get into our waterbodies and there's more we can do.

King County works with businesses, communities, and other government agencies on source control. What is “source control”? In this context, it’s finding sources of pollution, then stopping or reducing them before they reach a waterway. If you ever wondered how pollution travels through our communities and into waterbodies, or if you’ve ever wondered about how we are working to prevent pollution, or if you’ve ever thought about what you can do to help:

Work continues to update County website

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King County is updating its website with a new look that's designed to be simple and easy to use on all your devices.

It's a big site and moving everything will take some time—so don't be surprised if you see some pages with the old, familiar look and some with the new one.

We’ve moved the Industrial Waste pages into the new design. Below is what it now looks like. Let us know if you can’t find something you are looking for at

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Report spills to the sewer – get a copy of our “who to call” poster 

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Companies and facilities that discharge industrial wastewater to King County’s sewer system must post emergency phone numbers prominently in their work area. We recently updated our spill poster to include information in 6 languages. Your KCIW inspector will bring you a new poster during their next site inspection or visit.

Contact your assigned investigator for a copy or download the file to print.

Ask an Investigator or Specialist 

What are you curious about? Is there something you’ve always wanted to know about our Industrial Waste Program but have never asked? 

Ask a KCIW specialist!

Send an email with your question to and we’ll try to answer it in the next newsletter.

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