“In King County, the Sewer Capacity Charge is about $60–$70 per month and can last up to 15 years — adding thousands of dollars to a homeowner’s expenses.”
(Source: King County Wastewater Treatment Division)
If you’re thinking about selling a home in Seattle, or even buying one, you might be wondering, what the heck is a Sewer Capacity Charge and who’s supposed to pay it?
It’s one of those little details that doesn’t make the front page, but it can absolutely show up at the closing table if you’re not careful.
Today, The Madrona Group is here to bring you a better understanding of what the Sewer Capacity Charge is, how it works in Seattle and King County, and how it could affect your home sale or purchase. No confusing jargon, no doom-and-gloom — just real info you can actually use.
What to Expect from This Post:
- What exactly is a Sewer Capacity Charge?
- Why Seattle and King County charge it
- Where to find out if your property has a Sewer Capacity Charge
- Who typically pays this fee — buyer or seller
- How the charge impacts home sales
- How to pay it off before you sell
- Pro tips for sellers and buyers
- Common myths about the charge
- How The Madrona Group helps you avoid surprises
What Is the Sewer Capacity Charge?
The Sewer Capacity Charge is a special fee homeowners pay in King County and parts of Snohomish County to help cover the costs of major sewer system expansions.
Here’s the simple version:
- When a new property connects to the public sewer system, King County assesses a capacity fee.
- It’s billed separately from your regular water and sewer utility bill.
- Homeowners typically pay it monthly or quarterly for up to 15 years.
Fun fact:
Seattle’s Sewer Capacity Charge started back in 1990 and today averages about $70/month — but your exact amount depends on when the property connected.
Why Does Seattle Have a Sewer Capacity Charge?
Seattle’s booming, and big sewer systems aren’t cheap.
Instead of raising everyone’s sewer bills sky-high, King County decided that new connections should help pay for growth.
According to King County:
“The Sewer Capacity Charge ensures that growth pays for growth, helping to keep sewer rates lower for existing customers.”
Where Can You Check If a Property Has a Sewer Capacity Charge?
If you’re selling or buying a home in Seattle, King County, or southern Snohomish County, it’s important to check if the property has a capacity charge attached.
🔎 You can view the official map here:
👉 King County Capacity Charge Customer Service Area Map
What you’ll see:
- Properties highlighted that are subject to the charge
- Coverage areas that spill into parts of Snohomish County, like homes connected through the Alderwood Water & Wastewater District
Who Pays the Sewer Capacity Charge — Buyer or Seller?
Typically:
- The Sewer Capacity Charge stays with the property.
- That means the buyer inherits it after closing.
However:
- Buyers and sellers often negotiate who will pay the remaining balance.
- Some sellers offer to pay it off upfront to sweeten the deal.
If you’re prepping your home for sale, just like you would when getting your home ready for market, it’s smart to tackle this early.
How the Sewer Capacity Charge Impacts Seattle Real Estate Sales
If you’re listing your home for sale, here’s the reality:
- Buyers love transparency.
Disclosing the Sewer Capacity Charge upfront builds trust. - It could affect your home’s marketability.
If there’s a high remaining balance, it might be smart to offer to pay it off as part of your negotiation strategy. - It’s one of those hidden costs that can pop up if you’re not prepared — just like hidden costs when selling your home.
- It can impact appraisals.
Appraisers take utility costs into account, and a hefty monthly Sewer Capacity Charge could factor into affordability considerations.
Pro Tip:
If you’re preparing to sell your home, be sure you’ve reviewed other possible costs like capital gains taxes and closing costs, too.
Can You Pay Off the Sewer Capacity Charge Before You Sell?
Absolutely — and sometimes, you should.
Here’s how it works:
- Request a Final Payoff Statement
- Call King County Wastewater Treatment Division at 206-296-1450
- Or email CapChargeEscrow@kingcounty.gov
- Get the Total Payoff Amount
- It includes any remaining balance and interest.
- Make a Lump Sum Payment
- This clears the charge from the property forever.
- Get Written Confirmation
- This will be a big plus when you provide your seller disclosures.
Pro Tip:
Paying off the sewer charge before selling could make your listing more appealing — just like knowing how to handle hidden costs when selling your home.
Smart Tips for Handling Sewer Charges During a Sale
1. Find out early.
Pull your Sewer Capacity Charge statement right when you’re prepping your pre-listing inspections in Seattle.
2. Disclose it proudly.
Trust builds offers.
3. Offer to pay it off if needed.
It could make the difference between multiple offers or sitting stale.
4. Work with a sharp Seattle broker.
It’s one of the reasons working with a Seattle real estate broker makes all the difference.
Common Misunderstandings About Sewer Capacity Charges
- Myth: “It’s part of my sewer bill.”
Reality: It’s a separate charge billed by King County. - Myth: “Once I move out, it goes away.”
Reality: It stays with the property unless paid off. - Myth: “I don’t need to tell buyers about it.”
Reality: You should absolutely disclose it — hiding it could cause deal-breaking issues.
Final Thoughts on Sewer Capacity Charges
Selling a home in Seattle or Snohomish County means being ready for the curveballs — like sewer capacity charges.
They’re not scary once you know how they work, and addressing them head-on helps smooth the road to closing day.
At The Madrona Group, we pride ourselves on helping our clients avoid surprises so you can move through the Seattle housing market with confidence.
Whether it’s understanding sewer charges, capital gains tax, or who pays closing costs, we’re here to help you sell smarter, faster, and with way less stress.
Frequently Asked Questions (FAQs)
What is the sewer capacity charge?
It’s a special fee to help pay for new sewer infrastructure in King County and parts of Snohomish County.
How much is the sewer capacity charge?
About $70 per month, but it varies based on property type and connection year.
Can I pay the sewer capacity charge off early?
Yes! Request a payoff from King County and pay the lump sum before selling.
Does the buyer or seller pay the sewer capacity charge?
Typically the buyer inherits it, but sellers can agree to pay it off during negotiations.
Where can I find a map showing properties with a sewer capacity charge?
Check the King County Capacity Charge Map.
Takeaways
- Sewer Capacity Charges fund necessary sewer infrastructure for new developments.
- The charge stays with the property unless paid off before a sale.
- Paying off the charge can make your home more attractive to buyers.
- Always disclose sewer capacity charges early in the home selling process.
Share this post!
