(a) General. After May 1, 1964, no building; except commercial developments dwellings and single unit apartments with connected access to the potable water system, shall be constructed, enlarged, or moved unless the owner thereof shall make provision for a self-sustaining water supply system. This system shall consist of a well or rainwater collection area and cistern.
(b) Cistern capacity.
(1) Cisterns for dwellings, apartments and hotels shall have a minimum usable capacity of 10 gallons for each square foot of roof area for buildings of one story and 15 gallons for each square foot of roof area for buildings of two or more stories. If a dwelling shall have access to the potable water system and is verified by appropriate WAPA officials and service is installed, no cistern will be required.
(2) All other buildings shall have cisterns with a minimum usable capacity of 4 ½ gallons for each square foot of roof area except that churches and warehouses shall not be required to conform to this standard. If at any time buildings formerly used for churches and warehouses are converted to other uses compliance shall be required.
(3) Where a building has combined occupancy, such as apartment and store, required cistern capacity shall be 10 gallons for each square foot of roof area.
(4) One cistern may serve several buildings provided that its capacity is at least equal to the sum of the minimum required capacities for each building according to its use.
(c) Cisterns—Specifications.
(1) Cisterns shall be constructed of metal, masonry, concrete or other materials approved by the Commissioner and be maintained in a watertight and mosquito and rodent proof condition at all times. Metal cisterns shall be placed above ground level unless approved for underground installation in the building permit.
(2) Cisterns shall be located at a point free from flooding.
(3) An overflow of cross-section area at least equal to the combined cross-section areas of all inlets shall be provided on each cistern.
(d) Gutters and downspouts. Adequate gutters and downspouts shall be installed on all buildings for conducting water into cisterns. Gutters and downspouts shall be kept in good repair and free of dirt and debris at all times.
(e) Wells. A well supplying a safe, palatable, continuously adequate water supply may be used in lieu of a cistern. Such a well shall be dug and its compliance with the above requirements demonstrated to the Commissioner before a permit may be issued for the construction of a building without a cistern. The Department of Health shall certify as to the safety of the water for drinking purposes.