Since 1976 well and septic systems have been regulated and inspected by the Farmington Valley Health District. They will have information on the location and construction of these systems. They can be researched under the Document Search feature of the Farmington Valley Health District website.
For systems installed prior to 1976, the Building Department may have information. The earliest records in the Building Department's files generally date to about 1960. Contact the Building Department to see if they have these records.