Mill Valley Municipal Code Ch. 14.06 Groundwater Wells

No person shall drill, construct, remodel, reconstruct, destroy or abandon any groundwater well or test well without first submitting an application to and receiving a permit from the Director of Planning and Building of the City of Mill Valley. Such application shall be on a form provided by the City and shall provide information sufficient to determine that such well will comply with the provisions of this chapter, all laws of the state of California, and rules and regulations issued thereunder. The application shall be accompanied by a fee in an amount to be fixed from time to time by resolution adopted by the City Council of the City.

(Ord. 1363, 12/8/2025)

Notwithstanding any other provisions of law, every residential building which is required to be connected to a supply of potable water shall receive such water supply through a system owned and maintained by a public agency, or a public utility operating under the jurisdiction of the California Public Utilities Commission. Provided, however, that a residential building situated on a single family residential lot, legally created prior to the effective date of this section, may be connected to a groundwater well for the purpose of supplying potable water to such building, when all of the following conditions exist:

A. No portion of such lot lies within 125 feet of a water main to which connection can be made and which is owned and maintained by a public agency or a public utility operating under the jurisdiction of the California Public Utilities Commission.

B. The Mill Valley Fire Department certifies to the Director of Planning and Building that there is an adequate public water supply available for fire protection purposes.

C. The City Engineer certifies to the Director of Planning and Building that access is sufficient for well drilling equipment and for the importation of water in the event of well failure.

D. A yield test shall demonstrate that the well (or wells) will produce a minimum of one gallon per minute for a sustained pumping test of eight hours after the pumping level has been established or the well is pumped to the bottom. Such yield test shall be conducted from June 1st to November 15th, and shall be done by a licensed drilling or pump contractor, or a registered geologist. In the event of prolonged dry weather, the time period for the conduct of such yield test may be extended or certification be required by a registered geologist as to the well's productivity.

E. Prior to the connection to such well as a source of potable water supply, there shall be constructed upon the property a storage tank with a minimum capacity of 1,000 gallons to be used as a source of potable water supply during such periods as the well may be out of service for maintenance reasons or for pump repair.

F. The water supplied by such well shall meet all standards and conditions deemed necessary by the health officer for the protection of the public health, safety and welfare.

G. At the time of issuance of the well permit the applicant shall execute a hold harmless agreement relieving the City of Mill Valley, its officers, agents and employees of any liability for damages resulting from the construction and use of the well and the water supplied thereby. Such agreement shall bind the applicant, and successor owners of the property and shall be recorded in the office of the Marin County Recorder.

(Ord. 1363, 12/8/2025)

Permits may be issued for groundwater wells as a water source for irrigation, landscaping and other nonpotable uses. Before issuing a well permit for such purposes, the Director of Planning and Building shall submit a copy of the application to the public agency or public utility providing domestic water supply to be reviewed by it for the following purposes, among others:

A. Impact of total water requirements on the public water system in event of well failure.

B. Need for extension of the public water system to provide fire protection.

C. Need to install back flow prevention devices to protect the public water system.

D. All provisions for the use of well water shall conform to the applicable sections of the California Building Standards, including but not limited to, the Uniform Building, Plumbing, Mechanical and Electrical Codes, as adopted and set forth in Chapter 14.05 of the Mill Valley Municipal Code.

(Ord. 1363, 12/8/2025)

Any building utilizing a groundwater well as its source of potable water shall nevertheless connect to a public water system in the event that the water main owned and maintained by a public agency or a public utility operating under the jurisdiction of the California Public Utilities Commission is extended to within 125 feet of any portion of the lot upon which such building is situated.

(Ord. 1363, 12/8/2025)

Prior to issuance of a well permit, a fee shall be collected based on the fee schedules set by resolution of the City Council for Plumbing and Electrical Code applications.

(Ord. 1363, 12/8/2025)