Each year, the City of Denison publishes a report on its drinking water. It is packed with numbers and abbreviations, so here is a plain-English look at a few results homeowners tend to ask about. For every result, see the city’s full 2025 report.
Where the water comes from
Denison customers are served by surface water from two lakes. The city treats water from city-owned Lake Randell, which is supplemented by water transferred from Lake Texoma.
Hardness: 262 ppm
This is about 15 grains per gallon, which is very hard. It is the reason for scale on fixtures, spots on dishes and wear on water-using appliances. A water softener is the usual fix.
Total dissolved solids: 687 ppm
Total dissolved solids, or TDS, measures the minerals, salts and metals dissolved in water. Denison’s result is below the 1,000 ppm limit listed in the report, but TDS can affect taste. A reverse osmosis system is a common way to reduce TDS in drinking water.
Chloramine: 3.7 ppm average
Chloramine is the disinfectant the city uses to keep water safe as it travels through the system. The 2025 average was 3.7 ppm, under the 4 ppm limit. Some people notice its taste or smell, and filtration designed for chloramine can reduce it.
Lead and copper
The report lists a 90th percentile lead result of 1.82 parts per billion, against an action level of 15, and a copper result of 0.365 ppm, against an action level of 1.3. No sampled sites were over either level. Lead and copper usually come from household plumbing, so results can differ from one home to another, especially in older homes.
PFAS
Denison took part in the EPA’s fifth Unregulated Contaminant Monitoring Rule, which covers 29 PFAS, often called forever chemicals, plus lithium. The city reports that lithium was the only contaminant detected during that monitoring.
Your tap is what matters
A city report describes the public water system, not the water at your faucet, and it does not cover private wells. A home test can show you what is coming out of your own tap. Culligan of Denison serves Denison, Sherman, Durant and the surrounding area, and our local team can test your water at your home for free. Schedule your free water consultation.
