In many areas, mortgage lenders require water quality testing for properties with private wells. Testing a community well may not be required by individual lenders, as this is normally the purview of the municipality. Most lenders will accept a home inspector as an independent tester, who's required to check for bacteria, including E. coli and coliform. The results for such tests are usually available within 48 hours. Tests for minerals and other contaminants may take weeks to complete.
Public and private water supplies should be tested because they may be affected by the following:
No natural water source is completely free of impurities; contaminants and pathogens must be monitored and mitigated. With the passage of the Safe Drinking Water Act of 1974, the U.S. Environmental Protection Agency (EPA) set standards that determined the level for the safe consumption of 80 contaminants.
Water system plants test and treat water. However, these protections can and do fail. As a home inspector, it is your job to look for material defects in the home to ensure that it is safe for the occupants; adding water quality testing using a reliable test kit can enhance the information you report to your clients.
The EPA recommends that a residential water supply be tested annually for bacteria, nitrates, solids, pH levels, and other factors. The frequency of these tests may be increased based on the age of the home's occupants (infants are particularly susceptible to the effects of lead exposure), whether there are known risks of contamination, or whether any repair or construction work was recently conducted on or around the well or plumbing system. The EPA lists many conditions for whether a water quality test should be performed.
Guidelines provided by the World Health Organization (WHO) recommend that water samples be taken from locations that are representative of access points to water. Sampling should be done uniformly and at zones that are particularly high-risk. After collecting samples, testing should be done to determine the level of contamination. Remediation should be performed, if necessary; the EPA and WHO advise that remediation be carried out only by those trained to do so.