The four hour well yield test is used to determine the production or yield of the well in gallons per minute. When required by Environmental Health Services, this test must be performed by a licensed well driller or licensed pump contractor. A current four hour well yield report can be required for a number of reasons.
Depending upon the circumstance, it might be needed prior to building permit issuance or prior to issuance of an Environmental Health Services Final which is needed for a Certificate of Occupancy or as a requirement for a land division. Longer and more detailed testing may be required when there is concern of low well yields.