Construction of water supply wells
Summary of water district standards

Permit and license requirements
Permits are required for all wells. Please call (408) 265-2607, extension 2660, for permit applications. There are no fees for permits. Permit applications must be submitted with original signatures. Drilling contractors must have a current California C-57 contractor's license.

Minimum annular seal depth and radial thickness
A minimum 50-foot seal is required in bedrock wells. District well standards are more stringent than the state water well standards. Special sealing depth requirements will be determined by the district on case-by-case basis. Seal depth requirements will be specified either at time the permit is issued or following completion of a test hole. A minimum 2-inch radial thickness of annular seal is required by state well standards.

Acceptable sealing materials and seal placement method
Acceptable sealing materials are 27 sack neat cement, (four 94-pound bags/55-gallon drum), 10 sack cement sand grout, or hydrated high solids 20 percent bentonite slurry. No bentonite chips, pellets, or gel are allowed except for maximum 3-foot thick transition seal directly above filter pack.

Placement of sealing materials
Free fall of sealing material is not allowed if greater than 30 feet or if more than 3 feet of standing water exists in annulus. A tremie pipe must be used to place the sealing material if seal is more than 30 feet deep or water is present in the annulus. Tremie pipe must be placed such that no sealing material will free fall more than 30 feet or through more than 3 feet of standing water.

Santa Clara County Environmental Health Department approval
County Health Department approval is required for wells that will provide drinking water. Please call the County Health Department for information, (408) 918-3411. Any water supply wells with sanitary seals less than 50 feet deep must be preapproved by the County Health Department. All domestic and municipal water supply wells must be located at least 100 feet from any septic tank or leachfield.

Other
Before initiating drilling activities, check your property ownership deed and contact your local water retailer (if applicable) to determine if you own the rights to the water beneath your property.