A home water quality test checks your water for a range of contaminants and characteristics that affect safety, taste, and how hard your water is on plumbing and appliances. At minimum, a comprehensive test will screen for microbial contaminants, heavy metals, hardness minerals, pH, nitrates, and common chemical contaminants — giving you a clear picture of what is actually in your water rather than what you assume is there.

What a Standard Water Quality Test Measures

Most professional water quality tests cover several categories. Hardness is typically the first concern for Denver-area homeowners — Colorado’s Front Range water is notoriously hard, meaning it carries elevated levels of dissolved calcium and magnesium. The test quantifies how hard your water is so a treatment system can be properly sized.

pH is a measure of water’s acidity or alkalinity on a scale of 0 to 14, with 7 being neutral. Water that is too acidic — below about 6.5 — is corrosive to copper pipes and fixtures, which is why blue-green staining around drains and fittings is sometimes seen in homes with acidic water. Alkaline water above 8.5 can cause its own scaling and taste issues.

Heavy Metals: Lead, Iron, Copper, and Manganese

Heavy metal screening is one of the most important parts of a water quality test, particularly in older homes. Lead can leach from lead service lines or from solder in older interior plumbing — especially in Denver neighborhoods with housing stock from before the 1980s. There is no safe level of lead in drinking water, and it is odorless and colorless, so testing is the only way to know it is present.

Iron and manganese cause the rust staining and metallic taste that many homeowners notice but assume is just cosmetic. Elevated manganese, in particular, has been associated with neurological effects at high concentrations, so it is worth quantifying rather than ignoring. Copper shows up in homes where the water is acidic enough to leach it from pipes and fixtures.

Bacteria and Microbial Safety

Coliform bacteria testing — including total coliform and E. coli — is standard in tests for homes on private well water and is sometimes included in broader municipal tests. In Colorado, properties with private wells should test for bacteria annually, as agricultural runoff, septic proximity, and wildlife activity can all introduce contamination. Municipal water supplies are treated and monitored, but private wells have no such oversight.

Nitrates, Chemical Contaminants, and Seasonal Changes

Nitrates — often from agricultural fertilizer runoff or septic systems — are a particular concern in rural and semi-rural properties along the Front Range. High nitrate levels are dangerous for infants. A full-spectrum test may also screen for volatile organic compounds, chlorination byproducts like trihalomethanes, and in some areas, PFAS compounds.

A water quality test is a snapshot, not a permanent certification. Water quality can change seasonally — particularly after heavy rainfall or snowmelt, which can mobilize sediment and contaminants in both well and municipal systems. Testing after a significant plumbing change, a new home purchase, or any event that might affect your water source is good practice.

  • Water hardness (calcium and magnesium levels)
  • pH — acidity or alkalinity that affects corrosion and taste
  • Lead, iron, copper, and manganese
  • Total coliform and E. coli bacteria
  • Nitrates and nitrites
  • Chlorine, chloramines, and disinfection byproducts

What Happens After You Get the Results

Test results need to be interpreted correctly — a licensed plumber or water treatment specialist can review your numbers and recommend the right treatment, whether that is a whole-house filtration system, a reverse osmosis unit at the kitchen sink, a water softener, or a combination approach. The results drive the solution; guessing at a treatment without testing first often means spending money on equipment that does not address the actual problem.

Done’s team provides water quality testing and can recommend and install the right treatment systems for your specific results. Learn more on our water quality and treatment page, and visit our plumbing services page for the full range of services available.