1. (a) For the purpose of this part, “pumphouse” shall refer to any building or similar structure where components of the water system are located, including, but not limited to, pumps, electrical system and controls, treatment equipment, aboveground piping and valves, and appurtenances. If the building is used for other purposes in addition to water supply, the room(s) or area(s) of the building where components of the water system are located shall be considered the pumphouse and shall meet the requirements of this part.
2. (b) Pumphouses shall have screened gravity floor drains or equivalent with all floors pitched ¼ inch per foot toward the drains. Sump pumps shall not be acceptable in lieu of screened gravity floor drains. The drain pipes shall not discharge to any surface water and shall be screened at the discharge end to prevent small animals or insects from blocking flow. The pumphouse floor level shall be above the seasonal high water table.
3. (c) The layout of equipment and the design of the pumphouse shall provide for adequate space to allow operation and preventative maintenance.
4. (d) The design and materials shall include provisions to minimize vandalism damage to wells, doors, and roofs, and shall not have windows.
5. (e) The pumphouse walls and ceilings shall be fully insulated with materials that resist the attraction and residence of small rodents and similar pests.
6. (f) Construction materials shall be highly resistant to moisture, decay, and vandalism.
7. (g) The owner shall make every reasonable effort to design and construct the pumphouse at finished grade. For pumphouses that are required to be below grade due to site constraints, the pumphouse shall be not more than 5 feet below grade provided that an OSHA-compliant stairway access is provided.
8. (h) Except as allowed by (i) below, the floor elevation shall be at or above the flood hazard elevation determined pursuant to Env-Dw 405.06(b).
9. (i) If a proposed component of a drinking water system is proposed to be located below a flood hazard elevation as determined pursuant to Env-Dw 405.06(b) and there are no practicable alternatives to the proposed site, measures shall be taken to minimize the risk of flood damage. The designer shall document the mitigating measures or design modifications that will be taken to reduce the threats from locating the component below the flood hazard elevation.
10. (j) No component of a drinking water system shall be located in a Federal Emergency Management Agency (FEMA) designated floodway, with the exception of buried piping.
11. (k) To the extent practicable, drinking water facilities shall not be located in areas subject to a risk greater than 1% from earthquakes, fires, or other disasters that could damage the PWS or a portion thereof.
12. (l) A connection for a portable generator, including receptacle and manual transfer switch, shall be installed to readily accept portable power generators.

Source. (See Revision Note at part heading for Env-Dw 405) #10612, eff 6-1-14; ss by #14158, eff 12-25-24 (formerly Env-Dw 405.21)