How we check

Each number comes from a named official document or from arithmetic we show. The utility’s own current page always outranks this one.

How the official figures were read

WSSC Water’s website and the Maryland Department of the Environment’s block automated requests from the system used to prepare this desk. So their figures were read from the published text of its official pages and PDFs as carried by a search index, and not always by opening the page itself. Each source table links the official address so you can open it. EPA pages were opened directly, except where a page says otherwise.

If a figure affects a decision or a payment, open the linked page or look at your own bill first. If they differ, they are right and we are out of date.

What “our arithmetic” means

Bill figures use WSSC Water’s rates from July 1, 2026: a 90-day bill, a 5/8-inch meter, usage priced slice by slice through the four tiers, plus the Account Maintenance Fee ($34.58), the Infrastructure Investment Fee ($23.80) and about $15 for the Bay Restoration Fee. We don’t round usage to thousand-gallon steps as a real bill does, so yours can differ by a few dollars. No credits are applied.

Leak and sprinkler tables assume the extra water all falls in one 90-day bill. Hardness in grains per gallon is mg/L divided by 17.1. FY27 means the fiscal year that began July 1, 2026.

What we could not find

• FY21, FY22 and FY24 percentage rate rises: not found, so the chart leaves them out.
• Average age of WSSC Water mains in years: not published in anything we could read. We report the share over 50 years old.
• A county-by-county split of the lead service line inventory: not found.
• Month-by-month household water use for the service area: not found, so the summer page works from sprinkler arithmetic.

What we leave out

No forum anecdotes, no tests of our own, no estimates dressed as data. If a number can’t be sourced, the chart goes. Figures were last checked November 2, 2026.