About this chapter: Storm water and some liquid waste from a building can be a source of nonpotable water that can be used to reduce the volume of potable water supplied to the building. Chapter 13 provides the requirements for storage, treatment and distribution of this resource. This chapter also regulates the piping systems for reclaimed water supplied by a wastewater treatment facility.
Where chlorine is used for disinfection, the nonpotable water shall contain not more than 4 ppm (4mg/L) of chloramines or free chlorine when tested in accordance with ASTM D1253. Where ozone is used for disinfection, the nonpotable water shall not contain gas bubbles having elevated levels of ozone at the point of use.
Exception: Reclaimed water sources shall not be required to comply with these requirements.
Nonpotable water utilized for water closet and urinal flushing application shall be filtered by a 100-micron or fine filter.
Exception: Reclaimed water sources shall not be required to comply with these requirements. Graywater treatment systems installed in accordance with Section 1302.6.1 do not need to meet additional filtration requirements.
Nonpotable water outlets such as hose connections, open ended pipes and faucets shall be identified at the point of use for each outlet with signage that reads as follows: "Nonpotable water is utilized for [application name]. CAUTION: NONPOTABLE WATER — DO NOT DRINK." The words shall be legibly and indelibly printed on a tag or sign constructed of corrosion-resistant waterproof material or shall be indelibly printed on the fixture. The letters of the words shall be not less than 0.5 inch (12.7 mm) in height and in colors in contrast to the background on which they are applied. In addition to the required wordage, the pictograph shown in Figure 1301.3 shall appear on the signage required by this section.
ANY WORK ON THIS WATER SYSTEM" must be posted on any door providing entrance to the room.
Any storage tank or portion thereof that is above grade shall be protected from direct exposure to sunlight by one of the following methods:
- Tank construction using opaque, UV-resistant materials such as heavily tinted plastic, fiberglass, lined metal, concrete, wood, or painted to prevent algae growth.
- Specially constructed sun barriers.
- Installation in garages, crawl spaces or sheds.
Exemption. Tanks are not required if the graywater use is comprised of only subsurface irrigation and flows into a mulch basin system, where the mulch basin volume is three times the anticipated average daily flow.
Not less than one access opening shall be provided to allow inspection and cleaning of the tank interior. Access openings shall have an approved locking device or other approved method of securing access. Below-grade storage tanks, located outside of the building, shall be provided with a manhole either not less than 24 inches (610 mm) square or with an inside diameter not less than 24 inches (610 mm). Manholes shall extend not less than 4 inches (102 mm) above ground or shall be designed to prevent water infiltration. Finished grade shall be sloped away from the manhole to divert surface water. Manhole covers shall be secured to prevent unauthorized access. Service ports in manhole covers shall be not less than 8 inches (203 mm) in diameter and shall be not less than 4 inches (102 mm) above the finished grade level. The service port shall be secured to prevent unauthorized access.
Exception: Treated-water storage tanks that are less than 800 gallons (3028 L) in volume and installed below grade shall not be required to be equipped with a manhole provided that the tank has a service port of not less than 8 inches (203 mm) in diameter.
Storage tanks shall be tested in accordance with the following:
Storage tanks shall be filled with water to the overflow line prior to and during inspection. Seams and joints shall be left exposed and the tank shall remain water tight without leakage for a period of 24 hours.
- After 24 hours, supplemental water shall be introduced for a period of 15 minutes to verify proper drainage of the overflow system and that there are no leaks.
- The tank drain shall be observed for proper operation.
- The makeup water system shall be observed for proper operation and successful automatic shutoff of the system at the refill threshold shall be verified.
If the owner of an on-site nonpotable water reuse system or rainwater collection and conveyance system elects to cease use of, or fails to properly maintain such system, the system shall be abandoned and shall comply with the following:
- All system piping connecting to a utility-provided water system shall be removed or disabled.
- The distribution piping system shall be replaced with an approved potable water supply piping system. Where an existing potable pipe system is already in place, the fixtures shall be connected to the existing system.
- The storage tank shall be secured from accidental access by sealing or locking tank inlets and access points, or filling with sand or equivalent.
Storage tanks shall be located with a minimum horizontal distance between various elements as indicated in Table 1302.7.1.
LOCATION OF NONPOTABLE WATER REUSE STORAGE TANKS
|ELEMENT||MINIMUM HORIZONTAL DISTANCE FROM STORAGE TANK (feet)|
|Critical root zone (CRZ) of protected trees||2|
|Lot line adjoining private lots||5|
|Streams and lakes||50|
|Public water main||10|
For SI: 1 foot = 304.8 mm.