To keep your well safe, you must be sure that possible sources of contamination are not close by. Farther away is better.
Here are some guidelines:
Testing more than once a year may be warranted in special situations if:
Never hang anything from any part of a fire sprinkler system.
Buried storage tanks that contain petroleum and other hazardous chemicals may pose a safety hazard to those living in homes nearby.
Tanks should be tested for leaks, especially if testing has never been performed, the tank is unused, or the tank is old.
If there has been a leak, the situation should be remedied before the property is purchased. Testing requires one or more of the following technical measures:
pressure testing: Tanks are pressurized and then monitored for a period of time to observe for fluctuations that indicate a leak;
soil testing: Soil samples are taken from around the tank and sent to a lab for analysis. If the tests show chemicals have leaked, it is advisable for additional samples to be taken so that the extent of the contamination can be better understood;