Madison's Water Quality Report, Explained Well by Well

Madison Water Utility's 2025 annual report shows its water meeting all federal and state standards, but it doesn't print hardness in its main table. That lives in each well's own report: 2025 results ranged from 16 gpg (Well 20) to 34 gpg (Well 14). The utility's FAQ summarizes the city as very hard, 18 to 20 grains per gallon.

Two documents, two jobs

The annual report is a compliance summary. It lists detected substances across all wells, with the highest and lowest results and which wells had detections. A note under the table says the results may not represent the water at your home. The per-well reports, updated in April 2026, give each well's hardness, sodium, iron, manganese and PFAS results along with the neighborhoods it serves. For softening decisions, the well report is the one to read.

Hardness by well, 2025

• Well 14 (Spring Harbor, Regent, Shorewood Hills): 580 mg/L, 34 gpg.
• Well 6 (UW campus, Dudgeon-Monroe, Rocky Bluff): 26 gpg.
• Well 7 (Maple Bluff, Sherman Avenue): 23 gpg.
• Well 11 (Emerson East, Eken Park, Worthington Park): 26 gpg.
• Well 9 (Monona Drive to Stoughton Road, south of Cottage Grove Road): 25 gpg.
• Wells 13, 15, 16 and 27 (North side, East Washington corridor, Junction Ridge, Vilas and Greenbush): 22 gpg.
• Wells 29 and 31 (Far East and Southeast): 20 gpg.
• Wells 18, 25 and 26 (Park Street corridor, Sprecher East, west of Gammon Road): 19 gpg.
• Wells 12 and 28 (Midvale Heights, Orchard Ridge, Far West): 18 gpg.
• Wells 24 and 30 (Capitol area, south of Wingra Creek): 17 gpg.
• Well 20 (Southwest, south of Raymond Road): 16 gpg.

Neighborhoods are the utility's descriptions, shortened. Use its address lookup to confirm yours.

Sodium and chloride are climbing

The report calls out rising sodium and chloride at several wells, with historic road salt as the main cause. In 2025, chloride ranged from 1.0 to 200 ppm across wells and sodium from 2.2 to 66 ppm. The utility's ask is simple: use less salt outdoors, and set your softener to the correct hardness.

PFAS, iron and the rest

Six wells had at least one PFAS detection in 2025, all within EPA's limits for the six regulated compounds. Iron and manganese show up at moderate levels in several wells, and four wells have filters that remove more than 95% of both.

Very hard water points to a properly sized softener installation; drinking-water concerns point to reverse osmosis at the sink. The Madison water softener cost page has the price ranges.