Water Testing & House Sales

Standards and regulations for well construction and water testing have originated at several starting times in different government agencies and converged in time to the present configuration, which at times seems less than tidy. As a result, homeowners are subject to the old maxim of "buyer beware." As a general rule residents would be wise to remember that to own a house served by a private well is to own its water supply and any problems that may arise from it. Happily, well drillers are licensed professionals and wells are usually both safe and reliable, so that serious well and water contamination problems are rare.


In Connecticut, the Department of Consumer Protection licenses well drillers. New wells are constructed under permit by Local Health Departments, who approve the well location in compliance with the Connecticut Public Health Code before issuing the construction permit. After construction, the well driller must perform a yield test (number of gallons per minute) and file a well completion report with the Local Health Department. Yield limits vary greatly and minimum requirements are a factor of both the yield and the depth of the well, with lower yields requiring deeper wells.


Tests for drinking water quality are called potability tests and are conducted by laboratories licensed by the state. The tests measure a standard list of common water characteristics, which are divided into two levels of significance: "Maximum Contamination Level" and "Advisory Level". Water is considered safe to drink if no Maximum Contamination Level is exceeded. Well water for new houses must be tested and deemed safe to drink before a Certificate of Occupancy can be issued.
If private wells are tested within 6 months of the sale of an existing house the results will be sent to the local health department, however adverse test results do not result in Health Department action. In practice water testing is usually completed before, and is a condition of, closing. Remediation of adverse results is negotiated between buyer, seller and agents.


In rental situations, homeowners are required to provide "safe" drinking water for tenants, meaning water that does not exceed any Maximum Contamination Levels. However there is no requirement that water be regularly tested so that any testing would have to be initiated and paid for by the tenant unless some other agreement is reached.

The standard potability test is only one of many possible water tests, but the only one that is mandated in normal situations. Additional (and more expensive) testing may be indicated in areas that have been used for various commercial or industrial purposes.

Recording Permits

The Madison Health Department records well drilling permits, well completion reports and water test results on microfilm, which may be viewed at the Land Use Office at the Town Campus.

Treatment Systems

Water treatment systems to alleviate drinking water problems are supplied by private companies and are not licensed or regulated, except by their own professional organizations. (However discharge of backwash from water treatment equipment is subject to regulation). A wealth of information about private wells is available online.