D.C. Municipal Regulations (Last Updated: September 13, 2017) |
Title 12. CONSTRUCTION CODES SUPPLEMENT OF 2013 |
SubTilte 12-F. PLUMBING CODE SUPPLEMENT OF 2013 |
Chapter 12-F6. WATER SUPPLY AND DISTRIBUTION |
Section 12-F603. WATER SERVICE
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Strike Section 603.1 of the International Plumbing Code in its entirety and insert new Section 603.1 in the Plumbing Code in its place to read as follows:
603.1 Size of water service pipe. The water service pipe shall be sized to supply water to the structure in the quantities and at the pressures required in this code. The water service pipe shall be not less than 1 inch (25.4 mm) in diameter.
Insert new Sections 603.3 through 603.3.3 and Table 603.3.1 to the Plumbing Code to read as follows:
603.3 Water service piping protection. Water service piping shall be protected against backflow in accordance with Sections 603.3.1 through 603.3.3. This section shall not apply to one and two-family dwellings.
603.3.1 Water service piping backflow prevention. A backflow prevention device shall be installed on the water service pipe, downstream of the water meter, in compliance with Table 603.3.1, for every new water service, and for existing water services as required by Section 603.3.3. Backflow prevention devices shall be installed in accordance with manufacturer's installation instructions and shall be located upstream from any served water outlet.
603.3.2 High Risk Non-Residential Structure. Any building, structure or campus that is or contains a facility hereafter classified as a high risk non-residential structure shall be required to install a reduced pressure principle backflow prevention assembly conforming to ASSE 1013 on the water service connection. High risk non-residential structures include, but are not limited to, hospitals, hemoglobin dialysis centers, funeral homes or mortuary facilities, chemical manufacturing plants, car wash facilities, sewage treatment plants, auxiliary water supply systems, wells, dry cleaning plants, laboratories, facilities where radioactive materials are handled, and facilities with a water reuse system.
603.3.3 Existing water service piping. Installation of a backflow preventer in an existing water service pipe shall be required only in the following cases:
- Construction of a new structure reusing the existing service.
- Alteration of the existing water distribution system of the structure affecting fixtures that in aggregate account for more than 75 percent of the demand load of the existing installed system, calculated in accordance with Section 604.3, not including minor piping adjustments for fixture replacements.
- Addition to the existing water distribution system of the structure that will result in an increase of more than 50 percent in the demand load of the existing installed system, calculated in accordance with Section 604.3.
- The served existing structure has been or is heretofore classified as a high risk non-residential structure.
- When the existing water service pipe is being replaced.
Table 603.3.1 Water Service Backflow Prevention
Domestic Backflow Prevention Device
Facility type
Service Size
Type
Location
Note a
Residential or non-residential
1", 1 1/2" and 2"
Dual Check Valve Type (ASSE 1024- compliant)
On the discharge side of meter yoke
Note bNon-residential
3" and larger
Double Check BFP Assembly (ASSE 1015-compliant)
Inside facility, within 10 feet of water service point of entry
High Risk Non-residential
Any
Reduced Pressure Principle BF Preventer (ASSE 1013-compliant)
Fire Protection Backflow Prevention Device
Water Treatment
Type
Location
Note a
No chemical additives
Double Check Fire Protection BFP Assembly (ASSE 1015 –compliant)
Double Check Detector Fire Protection BFP Assembly (ASSE 1048 – compliant)
Inside facility, within 10 feet of water service point of entry
Treated with chemical additives
Reduced Pressure Principle Fire Protection BF Preventer (ASSE 1013 - compliant)
Reduced Pressure Detector Fire Protection BFP Assembly (ASSE 1047 - compliant)
For SI: 1 inch = 25.4 mm, 1 ft = 304.8 mm, 1 pound per square inch = 6.895 kPa.
a - Backflow prevention device shall always be located upstream from any water outlet.
b - Where inlet pressure to meter yoke is less than 42 psi, it is acceptable to locate the domestic backflow prevention device inside the facility, within 10 feet of water service point of entry.