Tests for pesticides, other organic contaminants and radon are expensive and usually not recommended unless you have reason to suspect contamination. Annual water testing is suggested to help monitor the quality of your private water supply. If you see a decline in quality, more thorough investigation is warranted. These records will provide valuable information on the history of your well if your water is ever contaminated. Follow your laboratory's sampling procedure when collecting water samples.
Many laboratories provide clean containers with detailed instructions on sample collection.
If one is not provided, use a clean plastic container. Rinse it three times with the well water before you collect the actual sample. Wash your hands prior to sampling and do not touch the inside of the container or lid. Let the water flow for about five minutes before sampling. Do not draw from an aerated faucet or a swing arm faucet.