12VAC5-635-290. Performance requirements; general.
A. The owner shall ensure that a rainwater harvesting system operates in compliance with the following performance requirements:
1. For a rainwater harvesting system designed to supply water for Tier 2, 3, or 4 end use, the owner or operator shall conduct treatment using a combination of filtration and disinfection technologies to the minimum standards described in 12VAC5-635-310.
2. If a rainwater harvesting system provides water for multiple end uses and treatment is not separated by end use, the highest treatment standard shall apply for all uses.
3. If a rainwater harvesting system provides water for multiple end uses and treatment is separated by end use, connection to distribution for each end use shall comply with the USBC.
B. The designer of a rainwater harvesting system shall consider the following factors:
1. The anticipated harvested rainwater characteristics and flow, including consideration of extremes of precipitation patterns. Excess precipitation not captured for storage shall be discharged as runoff. Insufficient precipitation that does not allow a rainwater harvesting system permitted for Tier 2, 3, or 4 end use to maintain sufficient storage shall be managed as described in 12VAC5-635-300.
2. The prevention of potentially harmful precipitation, such as that which could incorporate particulates from fires, from being captured and contained in the system.
3. The selection and sizing of components of sufficient structural integrity to minimize the potential of physical harm to humans and animals.
4. The sizing of the system in recognition of both the available collection area and number of users of the harvested rainwater. The designer of a Tier 4 rainwater harvesting system shall size the system pursuant to the following criteria:
a. A demand of 100 gallons per bedroom per day for residential systems using either a private well or public water for continuity of water supply pursuant to 12VAC5-635-300 C.
b. A demand of 150 gallons per bedroom per day for residential systems using hauled water for continuity of water supply pursuant to 12VAC5-635-300 C.
c. For nonresidential systems, the designer shall provide calculations supporting the anticipated demand.
Statutory Authority
§§ 32.1-12 and 32.1-248.2 of the Code of Virginia.
Historical Notes
Derived from Virginia Register Volume 41, Issue 5, eff. November 20, 2024.