(1)
General. All water for human consumption shall comply
with the requirements of the Safe Water Drinking Act (SWDA),
42 U.S.C. §
300f
et. seq.
(a) NFPA 13D multipurpose residential fire
sprinkler systems which utilize potable cold- water piping as part of a fire
sprinkler protection system in one-and two-family dwellings shall comply with
the requirements of
248
CMR
10.14. Installation of these systems
includes the direct connection of sprinkler heads to potable water piping. When
installing said system, the plumber shall adhere to the design plans of a
Massachusetts professional engineer, who is responsible for ensuring the design
complies with 248 CMR and NFPA 13D (2022 edition), including the requirements
as to pipe sizing and dimensions to ensure the proper functioning of the system
as well as the safety of the consumers who will rely on that system.
(b)
Potable Water
Supply.
1.
Buildings.
a. Every
building used for human occupancy or habitation shall be provided with an
adequate supply of potable water.
b. Every building used for human occupancy or
habitation shall be provided with an adequate supply of hot water.
2.
Use of Non-potable
Water Prohibited. Only potable water shall be accessible to
plumbing fixtures supplying water for:
a.
drinking;
b. bathing;
c. culinary use; or
d. the processing of food, medical or
pharmaceutical products.
(c)
Building Water
Piping. The building water piping shall be of sufficient size to
furnish water to the building in the quantities required elsewhere in
248 CMR
10.00.
(2)
Designing and Sizing the
Building Water Distribution System.
(a)
Methods to Be
Used.
1. The cold-water supply
from the meter or main control valve when no meter is present to all branches,
risers, final connection to fixtures and other connections shall be based on
the total demand and procedures outlined within
248
CMR
10.14.
2. The minimum size of a fixture supply pipe
shall be in accordance with
248
CMR
10.14(4):
Table
1.
3. Sizing the building
water main, branch distribution, risers and fixture supply piping shall be
determined using
248
CMR
10.14(4):
Tables
1,
2, and
3.
Exception: A system designed by a Massachusetts
professional engineer.
4. A demand
factor, as recognized in
248
CMR
10.14(4):
Table
2 shall be applied to determine the minimum diameter pipe size for the
building main and water distribution system piping.
5. The minimum size of a fixture water supply
pipe shall be in compliance with
248
CMR
10.14(4):
Table
1: Minimum Sizes of Individual Fixture Branches and Factor
Values.
6. The individual
fixture branch shall be extended to the fixture connector and terminate with a
fixture shut off valve.
7. Fixture
connectors shall not exceed 30 inches and shall be product accepted by the
Board.
Exception: Dishwashers, washing
machines and icemakers.
Table 1
Minimum Sizes of Individual Fixture Branches and Factor
Values
|
Type of Fixture or
Device
|
Nominal Pipe Size
(Inches)
|
Factor Value
|
|
Bathtub (with or without single shower
head)
|
1/2
|
2
|
|
Bidet
|
3/8
|
1
|
|
Drinking Water Station
|
3/8
|
1
|
|
Dishwasher (Domestic)
|
1/2
|
2
|
|
Dishwasher (Commercial)
|
3/4
|
6
|
|
Kitchen sink, Residential
|
1/2
|
2
|
|
Kitchen sink, Commercial (Pot and
Scullery)
|
3/4
|
6
|
|
Vegetable Prep or Bar Sink
(Residential)
|
1/2
|
2
|
|
Hand Wash Sinks
|
3/8
|
1
|
|
Shampoo Sinks
|
3/8
|
1
|
|
Lavatory
|
3/8
|
1
|
|
Utility Laundry Sinks 1, 2, or 3
compartments
|
1/2
|
2
|
|
Shower Valve (single head)
|
1/2
|
2
|
|
Shower Valve (Multiple heads)
|
3/4
|
6
|
|
Sinks (service, slop)
|
1/2
|
2
|
|
Sinks flushing rim
|
3/4
|
6
|
|
Laundry Valve
|
1/2
|
2
|
|
Urinal (flushometer type)
|
3/4
|
6
|
|
Toilet (tank type)
|
3/8
|
1
|
|
Toilet (flush valve type)
|
1
|
12
|
|
Hose Connections/Sillcocks/Wall
Hydrants
|
1/2
|
2
|
Table 2
|
Occupancy Use
|
Demand Factors
|
|
Residential
|
|
One or Two Family Dwelling
|
0.50
|
|
Multi-residential
|
0.35
|
|
Hotel
|
0.70
|
|
School
|
|
General
|
0.75
|
|
Shower Room
|
1.00
|
|
Institutional
|
|
General
|
0.45
|
|
Assembly
|
|
General
|
0.25
|
|
Restaurant, Cafe
|
0.70
|
|
Club House
|
0.60
|
|
Business and Mercantile
|
|
General
|
|
Industrial
|
0.25
|
|
Laundry
|
1.00
|
|
INDUSTRIAL
|
|
General, Exclusive of Process Piping
|
0.90
|
Table 3
Capacity Values for Service, Mains, Risers and/or
Branches
|
Nominal Pipe or Tubing Sizes
(inches)
|
Capacity Value
|
|
1/2
|
1 to 4
|
|
3/4
|
4.1 to 9
|
|
1
|
9.1 to 16.5
|
|
11/4
|
16.6 to 28
|
|
11/2
|
28.1 to 55
|
|
2
|
55.1 to 107.5
|
|
21/2
|
107.6 to 182.5
|
|
3
|
182.6 to 287.5
|
|
31/2
|
287.6 to 425
|
|
4
|
425.1 to 700
|
|
5
|
700.1 to 1100
|
|
6
|
1100.1 to 1300
|
8.
Example:
248
CMR
10.14(4):
Tables
1,
2 and
3 are used to determine the
size of the cold water main for a one family residence having the following
fixtures:
|
A
|
Two
|
Toilets (Tank type)
|
|
B
|
Two
|
Lavatories
|
|
C
|
One
|
Bathtub
|
|
D
|
One
|
Shower Stall
|
|
E
|
One
|
Utility Sink or Laundry Valve
|
|
F
|
One
|
Dishwasher (Domestic)
|
|
G
|
One
|
Kitchen Sink
|
|
H
|
Two
|
Wall Hydrants
|
Factor Values (248 CMR
10.14: from Table 1)
|
Hot
|
Cold
|
|
A
|
Two
|
Toilets (tank type) X 1
|
2
|
|
B
|
Two
|
Lavatories X 1
|
2
|
2
|
|
C
|
One
|
Bathtub
|
2
|
2
|
|
D
|
One
|
Shower Stall
|
2
|
2
|
|
E
|
One
|
Utility Sink or Laundry Valve
|
2
|
2
|
|
F
|
One
|
Dishwasher (Domestic)
|
2
|
|
G
|
One
|
Kitchen Sink
|
2
|
2
|
|
H
|
Two
|
Wall Hydrant
|
4
|
|
Total
|
12
|
16
|
28
|
a.
248
CMR
10.14(4):
Table
2 indicates a Demand Factor of 0.50 for a Single or Two family
dwelling.
b. Multiplying the total
Factor Value of 28 by the Demand Factor of 0.50 results in a Capacity Value of
14.0
c. A Capacity Value of 14 is
between 9.1 and 16.5 in
248
CMR
10.14(4):
Table
3 and the related pipe size is equals to a one-inch diameter
pipe.
(b)
Prevent Water Hammer.
1.
Installation and Design
Requirements.
a. All building
water supply systems in which quick acting valves and solenoid valves are
installed shall be provided with devices to absorb high pressures resulting
from the quick closing of these valves.
b. These pressure-absorbing devices shall be
air chambers that are provided with a means for restoring the air to the device
should the chambers become waterlogged, or other Product-accepted mechanical
devices.
c. Water pressure
absorbers shall be placed as close as possible to the quick acting valves and
shall be accessible for maintenance or replacement.
See248
CMR
1.14:
Example
2.
2.
Pressure Absorbing Devices. A mechanical pressure
absorbing device may be installed:
a. at the
ends of long pipe runs of pipe; or
b. connected to piping serving batteries of
fixtures.
3.
Mechanical Devices. Where mechanical devices are used,
the manufacturer's specifications shall be followed as to location and method
of installation.
10.14: Example 2 - Pressure Absorbing Device
Click to
view image
(c)
Minimum Pressures Required in
Water Distribution System. When sizing a water distribution piping
system, the minimum flow pressure at the point of discharge for each fixture
shall not be less than that shown in
248
CMR
10.14(4):
Table
4: Minimum Flow Pressure and Maximum Flow Rates.
Exception: On-demand domestic water heaters.
Table 4
Minimum Flow Pressure and Maximum Flow
Rates
|
Fixture or Device
|
Flow Pressure
PSI
|
Flow Rate
G.P.M.
|
|
Lavatory Faucet (Residential)
|
8
|
1.5
|
|
Lavatory Faucet (Non-residential)
|
8
|
.5
|
|
Kitchen or Bar Faucet (Residential)
|
8
|
2.2
|
|
Sink Faucet (Non-residential)
|
8
|
4.5
|
|
Bathtub Faucet
|
8
|
6
|
|
Laundry Valve or Faucet (Residential)
|
8
|
5
|
|
Shower Head
|
8
|
2*
|
|
Tank-Type Toilet
|
8
|
1.28
|
|
Flushometer-Type Toilet
|
15-20
|
1.28
|
|
Flushometer-Type Urinal
|
15
|
.5
|
|
Drinking Water Station
|
0.75
|
|
Outside Faucet or Hydrant
|
10
|
5
|
* Exception: Emergency showers as defined in
248
CMR 10.10 (12)
(d)
Inadequate Water
Pressure. Whenever water pressure from the street main, service,
or other source of supply is insufficient to provide flow pressures at fixture
outlets as required under
248
CMR
10.14(2)(c), a booster
pump and pressure tank or other means in compliance with
248 CMR
10.00 shall be installed on the building water supply
system.
1.
Water Pressure Booster
Systems. When water pressure in the public water main or
individual water supply system is insufficient to supply the probable peak
demand flow to all plumbing fixtures, a water pressure booster system shall be
installed:
a. In one, two and three-family
dwellings, a properly sized booster pump shall be installed.
b. In other than one, two and three-family
dwellings, a booster system shall be designed by a Massachusetts professional
engineer.
(e)
Excessive Water Pressure. If the pressure at any
plumbing fixture, device or appurtenance exceeds 80 PSIG, a pressure reducing
valve shall be installed on the water piping upstream of the device, or
appurtenance to limiting the pressure to 80 PSIG. Where pressure reducing
valves are installed, a pressure gauge with a minimum range of 0-150 PSIG shall
be installed within 24 inches downstream of the pressure reducing valve.
See 10.14:
Example 3.
Exception: Water service supply piping upstream and downstream
of a water pressure booster.
10.14: Example 3 - Pressure Reducing Valve
Click to
view image
(f)
Return Circulation - Where Required. Hot water supply
systems in buildings where the developed length of hot water piping from the
source of the hot water supply to the farthest fixture supply exceeds 75 feet
shall be of the total return circulation type. For purposes of
248
CMR
10.14, the "source" shall be the water
heater or the recirculation loop. The minimum size recirculating line shall be
1/2 inch.
(3)
Installation of the Building Water Distribution
System.
(a) All valves shall be
accessible.
(b)
Main
Control Valve.
1. A full-port
main control valve shall be installed in the water supply main on the discharge
side of each water meter or on the incoming water service where no meter is
present.
2. The valve shall be not
less than the size of the building water service pipe. See
10.14: Example 4.
3. A draw off valve shall be installed
upstream of main control valve on the discharge side of each water meter.
See 10.14:
Example 4.
10.14: Example 4 - Main Control Valve
Click to
view image
(c)
Branch and Riser
Valves.
1. A full-port valve
shall be installed at the base of each water supply riser when servicing
multiple fixtures on levels above the first floor. A draw off valve shall be
installed upstream of each riser valve. See 10.14:
Example 5.
2.
Branch valves installed servicing multiple fixtures shall be full
port.
3. In multistory buildings, a
full-port valve shall be installed at the top of each water supply that is an
upstream supply pipe from a booster system.
4. Dead Ends shall not be allowed.
(
see definition).
10.14: Example 5 - Risers
Click to
view image
(d)
Valves in Multiple Dwelling
Units. One or more main control valve shall be provided so that
the water to any unit may be shut off without stopping the flow of water to
other units. These valves shall be accessible to the unit supplied without
requiring access to other units. (e) All main control valves, branch/riser
valves and other devices installed on mains and branches of the water supply
system shall be of the full-port type.
(f)
Individual Fixture
Valves.
1. In all buildings,
water supply pipes feeding plumbing fixtures, devices, or appurtenances shall
be provided with a valve to shut off the water to that fixture, device, or
appurtenance. Exception: Residential shower valves,
tub and shower valves, tub fillers and other similar type fixtures.
2. All outside sillcocks, hose bibbs and wall
hydrants shall be separately controlled by a shutoff valve installed inside the
building.
(g)
Tank Controls. Supply lines from pressure or gravity
tanks shall be provided with valves at or near the tanks.
(h)
Water Heating Equipment
Valve. The cold-water branch to each hot water storage tank or
water heater shall be provided with a valve located near the equipment and
above the top of the tank.
See 10.14:
Example
6.
10.14: Example 6 - Valve for Water Heater
Click to
view image
(i)
Drain Valves.
1. In
other than single family homes, a drain valve shall be installed at all low
points of piping so that every portion of the water piping system can be
drained.
2. An accessible drain
valve shall be required upstream and near the meter or main control valve.
See 10.14: Example 4.
(j)
Metering Devices with Check
Valves. When a metering device with a check valve or backflow
preventor is installed creating a closed system, a properly sized thermal
expansion tank shall be installed as close as possible to the metering
device.
(k)
Hose
Connections.
1. Outside Hose
connections, sillcocks or wall hydrants shall be installed in all residential
buildings no more than 100 feet apart.
2. In all commercial buildings, Sillcocks and
hose connections shall only be required in:
a. mechanical rooms;
b. mechanical penthouses; or
c. mechanical areas of similar use and
nature.
3. A backflow
preventer or vacuum breaker shall be installed on all sillcocks, hose
connections and wall hydrants including faucets that incorporate a hose thread
outlet.
(l)
Prohibited Valves and Connections.
1. Saddle valves.
2. No water supply line shall be tapped,
burned, welded, or drilled, other than mechanical devices that have been
Product-accepted by the Board which are designed and engineered to create
penetration in piping for specific joining methods may be
used.
(4)
Disinfection of Potable Water System Piping. When
necessary, the Inspector shall require that a Potable water distribution
system, or any part thereof, which has been installed or repaired may require
disinfection in accordance with one of the following methods before it is
placed in operation:
(a) The system, or part
thereof, shall be filled with a water and chlorine solution which contains 50
parts per million of available chlorine; and the same shall then be allowed to
stand six hours before the system, or part thereof, is flushed and returned to
service.
(b) The system, or part
thereof, shall be filled with a solution which contains 100 parts per million
of available chlorine, and the same shall then be allowed to stand two hours
before the system, or part thereof, is flushed and returned to
service.
(c) Where it is not
possible to disinfect a potable water storage tank as provided by
248
CMR
10.14(7)(a) or (b), the
entire interior of the tank shall be swabbed with a solution which contains 200
parts per million of available chlorine; and the solution shall then be allowed
to stand two hours before the tank is flushed and returned to service. For a
potable water filter or similar device, the Massachusetts Department of
Environmental Protection shall determine the dosage.
(5)
Hot Water Supply
System.
(a) In all occupied
premises and structures, hot water shall be supplied to all plumbing fixtures
and equipment used for bathing, washing, culinary purpose, cleansing, laundry,
or building maintenance.
(b) Hot
water storage systems shall be designed to adequately accommodate the fixtures
being served.
(c) The maximum
temperature of domestic hot water in residential buildings shall not exceed
130°F. Plumbing fixtures requiring higher temperatures for their proper use
and function, such as dishwashers and hot water dispensers shall be exempted
from 248 CMR
10.14.
Minimum and Maximum Hot Water Temperatures
|
Hot Water Temperatures
(Fahrenheit)
|
|
Minimum
|
Maximum
|
|
Residential
|
120
|
130*
|
|
Water Entering the Sanitary Drainage
System
|
150
|
|
Shower Valve
|
120
|
120
|
|
Tub Filler
|
120
|
120
|
|
Public & Employee Lavatory
|
120
|
120
|
|
Residential Lavatory
|
120
|
130
|
|
Emergency Showers & Eyewash
|
60
|
100
|
|
Hand Sink in Commercial Kitchen
|
120
|
120
|
|
Kitchen Type Sink in Office
|
120
|
120
|
|
Service Sink & Scullery Sink
|
120
|
140
|
|
* See 10.14 (5)(c) for
Exception
|
|
(6)
Tank Type Water Heaters and
Storage Tanks.
(a)
Working Pressure of Storage Tank. To determine the
working pressure of a hot water tank as required by M.G.L. c. 142, § 18E,
the street or service pressure only shall be considered, unless a water
pressure booster system is used to raise the house pressure above the street
pressure.
(b)
Tank
Drains. A storage tank shall be equipped with a drain valve for
emptying at the tank lowest point accept when otherwise allowed by the
Board.
(c)
Cold Water
Supply.
1. A check valve shall
not be installed in the cold-water supply to any hot water heater or hot water
storage tank.
2. A properly sized
thermal expansion tank may be installed to prevent excessive pressure from
developing due to thermal expansion.
(d)
Prohibited Methods of Water
Heating.
1.
Hot Water
Generators. No coils, boosters or other hot water heating devices
shall be installed in direct contact with the heat generating source of any
building heating system or heating unit.
2.
Systems Without Automatic
Control. No domestic hot water storage system, connected with or
to, a direct heating device or appliance, shall be installed in any basement of
any building or other unattended area unless such installation has fully
automatic control to prevent raising of the temperature of the water in any
part of the storage tank to 212°F.
(e)
Large Volume Water Heaters
and Storage Tanks.
1. Water
heaters and storage tanks shall be stamped as ASME compliant when:
a. Installed in other than a private
residence or a single condominium unit where the heater is serving only that
unit;
b. Have a storage capacity of
over 120 gallons and/or a recovery equal to or greater than 200,000 B.T.U.;
and
c. are direct or indirect fired.
When determining the B.T.U. rating for an indirect fired water heater, the
maximum output of the stored or transferred energy shall be utilized.
Examples: An 80-gallon tank with a
recovery rate 210,000 BTU must comply with ASME requirements. Two tanks
installed, each with 100-gallon capacity with an indirect water heater with a
recovery rate of 199,000 BTU feeding tanks shall meet ASME requirements.
Exception: Water heaters and storage
tanks which meet the following requirements:
a. The tank conforms with the following
UL-174 testing:
i.
Section
33. Two times the maximum working pressure or 300 PSIG
maximum;
ii.
Section
22. 150 PSIG and 210° maximum.
b. The tank has a minimum of a ten year
warranty
c. A maximum of four tanks
may be installed in tandem.
2.
ASME Data Sheet.
a. Copies of an ASME data sheet attesting to
the conformance with the requirements of the applicable section of the Code and
signed by an authorized and qualified inspector shall be furnished to the owner
and/or installing contractor.
b. A
copy of the data shall be permanently displayed in a suitable mounting on a
wall adjacent to the water heater.
(f) Safety Devices for Water Heaters Safety
devices to be used on hot water tanks, tankless and on-demand heaters shall be
installed to comply with the provisions of M.G.L. c. 142, § 19 and
Standard ANSI 221.22.
1.
Pressure
Relief Valves.
a. Pressure relief
valves installed on direct-fired water heaters having up to 200,000 BTU per
hour input shall have a listed rating of not less than the heater
input.
b. Pressure relief valves
for on-demand water heaters shall have a listed rating of not less than the
water heater input.
c. For tankless
heaters connected to low pressure steam and hot water heating boilers, the
pressure relief valve shall be sized according to
248
CMR
10.14(6)(f):
Table 5, as follows:
Table 5
|
Heater Rating
(GPM)
|
Valve Size
|
|
Up to 5
|
1/2-inch
|
|
Over 5 up to 20 Standard Z21.22
applies
|
3/4-inch
|
|
Over 20 up to 50
|
1-inch
|
|
Over 50
ASME Standard applies
|
1 - 11/4-inch
|
2.
Combination Temperature and
Pressure Relief Valves. (T&P) All storage water heating
equipment capable of heating water in excess of 212°F shall be equipped
with a properly sized T&P relief valve.
a.
T&P relief valves shall meet the requirements of pressure relief valves as
provided in
248
CMR
10.14(6)(f)1.
b. A T&P valve shall be installed in a
tapping directly in or on the tank, within 12 inches of the top of a vertical
tank, or within six inches of the top of a horizontal tank, with no fittings
between the valve and the tank, except that a bushing may be used to reduce the
tapping to fit the valve, or the valve shall be installed in the hot water
outlet pipe as close to the top of the tank as possible but in no case more
than five inches from the top of the tank.
c. The discharge outlet if the T&P relief
valve shall be full-size and pipe using non-ferrous material or tubing rated to
withstand the maximum relief valve temperature with no shut-off, to a fixture
or a point to within twelve inches of the floor.
d. Heaters and storage tanks with ratings in
excess of 200,000 BTU shall be equipped with T&P relief valves in
compliance with the requirements of ASME and the current ANSI Z21.22
Standard.
3.
Vacuum Relief Valves.
a. Tank type water heaters and storage tanks
shall be protected against loss of water from siphoning due to loss of supply
pressure by a vacuum relief valve installed in the cold-water supply line at a
level above the top of the heater or tank with no shut off valve installed
between the vacuum relief valve and the tank.
b. Vacuum relief valves shall be a minimum of
one pipe size smaller than the tank drain size.
c. Vacuum relief valves may be installed in
multiples and in compliance with
248
CMR
10.14(6)(f)3.
Table 6.
Table 6
|
Vacuum Valve Sizing
Chart
|
|
Size of Tank Drain
|
Number of 1/2" Valves Required
|
Number of 3/4" Valves Required
|
|
1/2"
|
1
|
|
|
3/4"
|
1
|
|
|
1"
|
2
|
1
|
|
13/4"
|
3
|
2
|
|
11/2"
|
4
|
3
|
|
2" and Larger
|
5
|
4
|
(g)
Combination Potable
Water/Space Heating System. These systems shall comply with the
following requirements.
See 10.14:
Example 7.
1. The maximum distance from the water heater
to the fan coil and returning to the water heater shall not exceed 100 feet in
developed length.
2. All piping
materials between the water heater and coil shall be incompliance with
248
CMR
3.04:
Product, Design, and
Testing Standards and
248
CMR
10.06.
3. Must contain an electronically controlled
pump timer which operates at least once every six hours for a minimum of 60
seconds.
4. A properly sized
potable water expansion tank shall be installed.
5. A mixing valve for service to the plumbing
fixtures shall be installed.
10.14: Example 7
Combination Potable Water/Space Heating
System
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(h)
Identification Tags for Water
Heaters. Metal or foil tags permanently attach to most water
heaters are considered in compliance with the provisions of M.G.L. c. 142,
§ 17.
(7)
Protection of Potable Water Supply.
(a)
General. A
potable water supply system shall be designed, installed, and maintained in
such manner as to prevent contamination from non-potable liquids, solids, or
gases from being introduced into the potable water supply through cross
connections or any other piping connections to the system.
(b)
Identification of Potable and
Non-potable Water. In all buildings where potable water and
non-potable water is installed within the same building or structure, the
following additional conditions must be satisfied as well as those conditions
required for each individual piping system:
1. The potable and non-potable piping systems
shall be labeled or painted in the following manner:
a. at a minimum of every ten feet;
b. at all changes of direction;
c. on each side of a penetration through a
partition, wall, ceiling or roof;
d. at every shut off valve;
e. for potable water (color-coded green) and
non-potable water (color-coded yellow), the labels shall be;
i. black lettering indicating "safe water"
for potable and "unsafe water" for non-potable;
ii. the letters shall be sized equal to a
minimum of the pipe diameter. However, for piping with a diameter exceeding two
inches, said lettering does not need to be larger than two inches.
f. Non-potable water shall be
identified at each outlet location.
(c)
Cross Connection
Control.
1. Cross connections
between potable water systems and other systems or equipment containing water
or other substances of unknown or questionable safety are prohibited; except
when and where, as approved by the Massachusetts Department of Environmental
Protection (DEP) or its designee, suitable protective devices such as the
Reduced Pressure Zone Backflow Preventer or equal are installed, tested, and
maintained to insure proper operation on a continuing basis.
2. No plumbing permit shall be issued for
cross connection installations that require Reduced Pressure Zone Backflow
Preventers or Double Check Valve Assemblies until the application for a permit
is accompanied by a letter of approval from the Massachusetts (DEP) or its
designee.
3. The (DEP) or its
designee shall be the authority having jurisdiction for the type of cross
connection control required. The (DEP) shall be responsible for preventing the
contamination of drinking water to the last free flowing outlets or consumer's
tap.
(d)
Interconnections.
1.
Individual Water Supplies. Cross connections between
an individual water supply and a potable public supply shall not be made unless
specifically approved by the Massachusetts (DEP).
2.
Public Water
Supplies. Interconnection between two or more public water
supplies shall be permitted only with the approval of the health authority
having jurisdiction.
(e)
Foreign Materials. No materials or substances that
could produce either toxic condition, taste, odor, or discoloration in a
potable water system shall be introduced into or used in such
systems.
(f)
Used
Piping. Piping which has been used for any other purpose than
conveying potable water shall not be used for conveying potable
water.
(g)
Self Feeding
Water Connections to Heating Boilers.
1. Potable water connections to a heating
boiler shall be provided with an approved back flow preventer or air gap in the
water line to prevent cross connection.
2. Backflow preventers shall not be required
on manually controlled water supply lines to residential type steam and/or
gravity fed hot water space heating systems.
(h)
Prohibited Connections to
Fixtures and Equipment. Connection to the potable water supply
system for the following shall be protected against backflow:
1. bidets;
2. operating, dissection, embalming, and
mortuary tables or similar equipment -- in such installation, the hose used for
water supply shall terminate at least 12 inches away from every point of the
table or attachments;
3. pumps for
non-potable water, chemicals, or other substances; note that priming
connections may be made only through an air gap;
4. building drainage, sewer, or vent system;
and
5. any other fixture of similar
hazard.
(i)
Refrigerating Unit Condensers and Cooling Jackets.
1. Except where potable water provided for a
refrigerator condenser or cooling jacket is entirely outside the piping or tank
containing a toxic refrigerant, with two separate thicknesses of metal
separating the refrigerant from the potable water supply the inlet connection
shall be provided with an approved double check valve installation.
2. Also adjacent to and at the outlet side of
the check valve, an approved pressure relief valve set to relieve at five PSIG
above the maximum water pressure at the point of installation shall be provided
if the refrigeration units contain more than 20 pounds of
refrigerants.
(j)
Chemical Cleaning Dispensers.
1. Devices directly connected to the potable
water system. (hard piped)
a. Shall require a
plumbing permit.
b. The public
water supplier shall determine the proper backflow device to be
installed.
2. Devices
connected to the hose end of a faucet:
a.
Shall not require a plumbing permit;
b. All dispensers shall have an Air Gap or,
an alternative Certification of Listing under the ASSE 1055B
Standard.
c. A pressure bleeder
device shall be provided which will visually free flow water through the
atmosphere from the faucet connection to a sink or drain. The bleeder device
shall connect to the water source utilizing a quick disconnect
coupling.
d. The Device that
attaches to the Faucet shall be so arranged, so it is one piece that will not
allow theremoval of the bleeder from the Quick disconnect portion of this
device.
(k)
Water Recycling/Re-use Prohibited.
1. Water used for cooling of equipment or
other processes shall be discharged into the drainage system through an air
gapped indirect waste. Under conditions where water shortage may occur, the
water used for cooling may be used for non-potable purposes. Water used for
cooling of equipment or other processes shall not be returned to the potable
water system.
2.
Exceptions. Water recycling systems may be installed
if Special-permission under
248
CMR
3.04(3) has been
granted by the Board. Systems include, but limited to:
a. dedicated gray water systems;
b. black water systems;
c. on site wastewater treatments
systems;
d. systems
Product-accepted by the Board shall not require Special Permission.
(l)
Protection Against Backflow and Back siphonage.
1.
Water Outlets. A
potable water system shall be protected against backflow and back siphonage in
accordance with M.G.L. c. 111, § 160A, and 310 CMR:
Department of
Environmental Protection relative to protection of the potable water
supply.
a.
Air Gap.
An air gap as defined in
248
CMR
10.03 between the potable water outlet
and the flood level rim of the fixture it supplies or between the outlet and
any other source of contamination.
i. The
minimum required air gap shall be measured vertically from the lowest end of a
potable water outlet to the flood rim of the fixture or receptacle into which
it discharges and shall be twice the effective opening of the potable water
outlet.
ii. If the outlet is found
to be at a distance that is less than three times the effective opening away
from a wall or similar vertical surface; the minimum required air gap shall be
three times the effective opening of the outlet.
iii. In no case shall the minimum required
air gap be less than shown in
248
CMR
10.14(8):
Table
7:
Minimum Air Gaps for Plumbing Fixtures:
b.
Backflow
Preventer. A backflow preventing device or vacuum breaker to
prevent the drawing of contamination into potable water system.
Table 7
Minimum Air Gaps for Plumbing Fixtures
|
Minimum Air Gaps For Plumbing
Fixtures
|
Minimum Air Gap
|
|
When not affected by a near
wall
|
When affected by a near
wall
|
|
Lavatories and other fixtures with effective openings
not greater than one half inch in diameter.
|
1 inch
|
1.50 inches
|
|
Sink, laundry sinks, goose neck bath faucets and
other fixtures with effective openings not greater than three quarters of an
inch diameter.
|
1.5 inches
|
2.25 inches
|
|
Over rim bath fillers and other fixtures with
effective openings not greater than one-inch diameter.
|
2 inches
|
3 inches
|
|
Effective openings greater than one
inch
|
2 times the diameter of the effective
opening
|
2 times the diameter of the effective
opening
|
2.
Devices for the Protection of
the Potable Water Supply. Approved backflow preventers or vacuum
breakers shall be installed on any plumbing fixture or equipment where the
potable water supply outlet may be submerged and cannot be protected by a
minimum air gap.
a.
Labeling.
i. Piping
after each device shall be labeled as "Water Subject to Questionable Safety" in
accordance with
248
CMR
10.14(8)(b)1.a. through
f.
3.
Installation of Devices.
a.
Vacuum Breakers.
i. Vacuum breakers shall be installed with
the critical level at least six inches above the flood level rim of the fixture
they serve and on the discharge side of the last control valve to the
fixture.
ii. No shut-off valve or
faucet shall be installed beyond the vacuum breaker.
iii. For closed equipment or vessels such as
pressure sterilizers the top of the vessel shall be treated as the flood level
rim but a check valve shall be installed on the discharge side of the vacuum
breaker.
b.
Reduced Pressure Zone Backflow. A reduced pressure
zone type backflow preventer may be installed subject to full static pressure.
Where damage may occur to the building or structure due to water discharge from
the vent port precautions shall be taken.
c.
Devices of All
Types.
i. Backflow and back
siphonage preventing devices shall be accessibly located preferably in the same
room with the fixture they serve.
ii. Installation in utility or service
spaces, provided they are readily accessible, is also
permitted.
4.
Tanks and Vats - Below Rim Supply.
a. Where a potable water outlet terminates
below the rim of a tank or vat and the tank or vat has an overflow of diameter
not less than given in
248
CMR
10.14(6):
Table
8:
Sizes of Overflow Pipes for Water Supply Tanks,
the overflow pipe shall be provided with an air gap as close to the tank as
possible.
b. The potable water
outlet to the tank or vat shall terminate a distance not less than 11/2
times the height to which water can rise in the tank above the top of the
overflow.
c. This level shall be
established at the maximum flow rate of the supply to the tank or vat and with
all outlets except the air gap, overflow outlet closed.
d. The distance from the outlet to the-high
water level shall be measured from the critical point of the potable water
supply outlet.
Table 8
Sizes of Overflow Pipes for Water Supply
Tanks
|
Maximum Capacity of Water Supply Line to
Tank
|
Diameter of Overflow Pipe (inches ID)
|
|
0 - 50 G.P.M.
|
2
|
|
51 - 100 G.P.M.
|
21/2
|
|
101 - 165 G.P.M.
|
3
|
|
166 - 355 G.P.M.
|
4
|
|
356 - 640 G.P.M.
|
5
|
|
641 - 1,040 G.P.M.
|
6
|
|
OVER 1,040 G.P.M.
|
8
|
5.
Connections Not Subject to
Back Pressure.
a. Where a water
connection is not subject to back pressure, a non-pressure type vacuum breaker
shall be installed on the discharge side of the last valve on the line serving
the fixture or equipment.
b. A list
of some conditions requiring protective devices of this kind is given in in
10.14
Table 9:
Cross Connections Where Protective
Devices Are Required and Critical Level (C-L) Settings for Backflow
Preventers.
Table 9
Sizes of Drain Pines for Water Tanks
|
TANK CAPACITY
(Gallons)
|
DRAINPIPE SIZE (Inches)
|
|
Up to 750
|
1"
|
|
751 - 1,500
|
11/2"
|
|
1,501 - 3,000
|
2"
|
|
3,001 - 5,000
|
21/2"
|
|
5,001 - 7,500
|
3"
|
|
7,500 and Larger
|
4"
|
6.
Barometric Loop.
Water connections not subject to back pressure where an actual or potential
backflow or back siphonage hazard exists may in
lieu of
devices specified in
248
CMR
10.14(8)(k)2., be
provided with a 35-foot barometric loop. Barometric loops shall precede the
point of connection.
7.
Pressure Type Vacuum Breakers. Water connections not
subject to backpressure where an actual or potential backflow or back siphonage
hazard exists may be protected by the installation of a pressure type vacuum
breaker, provided that such device is installed with the critical level a
minimum of 12 inches above the highest outlet or fixture served by the
connection.
8.
Anti-siphon or Backpressure Valves.
a. An anti-siphon or backpressure valve shall
be installed on any chemical metering pump that pumps any chemical into a
potable water supply to prevent back siphonage.
b. The anti-siphon or back-pressure valve
must be spring loaded and set at a minimum of five PSIG (An example may be an
anti-siphon or back-pressure valve installed on a positive displacement
metering pump's discharge line and pumping sodium hypochlorite into a water
main at a well house for disinfection purposed.)
Table 10
Cross Connections Where Protective Devices Are Required
and Critical Level (C-l) Settings for Backflow Preventers
|
Fixture or Equipment
|
Method of Installation
|
|
Aspirators and ejectors
|
C-L at least six inches above flood level or
receptacle.
|
|
Dental units
|
On models without built-in vacuum breakers -- C-L at
least six inches above flood level rim of bowl.
|
|
Dishwashing machines
|
C-L at least six inches above flood level of machine.
Install on both hot and cold water supply lines.
|
|
Flushometers (closet and urinal)
|
C-L at least six inches above top of fixture
supplied
|
|
Garbage can cleaning machine
|
C-L at least six inches above flood level of machine.
Install on both hot and cold water supply lines.
|
|
Hose outlets
|
C-L at least six inches above highest point on hose
line.
|
|
Laundry machines
|
C-L at least six inches above flood level of machine.
Install on both hot and cold water supply lines.
|
|
Lawn sprinklers
|
C-L at least 12 inches above highest sprinkler or
discharge outlet.
|
|
Steam tables
|
C-L at least six inches above flood
level.
|
|
Tank and vats
|
C-L at least six inches above flood level rim or
line.
|
|
Trough urinals
|
C-L at least six inches above perforated flush
pipe.
|
|
Flush tanks
|
Must be equipped with approved ball cock. Where ball
cocks contact tank water they must be equipped with a vacuum breaker at least
one inch above the overflow outlets. Where a ball cock does not contact tank
water install the ball cock outlet at least one inch above the overflow outlet
or provide a vacuum breaker as specified above.
|
Table 11
Acceptable Types of Backflow Preventers for Prevention of
Cross Connections on Potable Water
|
AG = Air Gap RPBP = Reduced Pressure
Backflow Preventer
DCVA = Double Check Valve
Assembly
AVB = Atmospheric Vacuum
Breaker
PVB = Pressure Vacuum Breaker
BPIAV = Backflow Preventer
w/Intermediate Atmospheric Vent
|
|
Type of Hazard on
Premises
|
Acceptable Types of Backflow
Preventors
|
Comments*
|
|
AG
|
RPBP
|
DCVA
|
AVB
|
PVB
BFPAV
|
|
1. Sewage Treatment Plant
|
X
|
X
|
|
2. Sewage Pumping Station
|
X
|
X
|
|
3. Food Processing
|
X
|
X
|
X*
|
*If no health hazard exists
|
|
4. Laboratories
|
X
|
X
|
X*
|
*If no health hazard exists
|
|
5. Fixtures with hose threads on
inlets
|
X
|
X
|
X
|
X
|
In addition to an air-gap separation, all fixtures
that have threaded hose type connections shall at a minimum, be equipped with
an AVB
|
|
6. Hospitals, Mortuaries &
Clinics
|
X
|
X
|
|
7. Plating Facilities
|
X
|
X
|
|
8. Irrigation Systems**
|
X
|
X
|
X*
|
X**
|
Each case should be evaluated individually.
*An AVB may be used if no back pressure is possible
and no health hazard exists.
** A PVB should be installed if back pressure is
possible.
|
|
9. Systems or Equipment Using Radioactive
Material
|
X
|
X
|
|
10. Submerged Inlets
|
X
|
X
|
X*
|
*If no health hazard exists and no back-pressure is
possible
|
|
11. Dockside Facilities
|
X
|
X
|
|
12. Valves Outlets or Fixtures with Hose
Attachments
|
X
|
X
|
X*
|
Each case should be evaluated
|
|
individually
*If no health hazard exists and no back-pressure is
possible
|
|
13. Commercial Laundries & Dry
Cleaners
|
X
|
X
|
|
14. Commercial Dishwashing Machines
|
X
|
X
|
X*
|
*If no health hazard exists
|
|
15. High- and Low-Pressure Boilers
|
X
|
X*
|
*If chemicals are added
|
|
16. Low Pressure Heating Boilers
|
X
|
Residential and small commercial having no chemicals
added
|
|
17. Photo Processing Equipment
|
X
|
X
|
|
18. Reservoirs - Cooling Tower Recirculating
Systems
|
X
|
X
|
|
19. Fire Protection Systems: For cross connection
control, fire protection systems may be classified on the basis of water source
and arrangement of supplies as follows: (a) Class 1: Direct connection from
public water system mains only; no pumps, tanks, or reservoirs; no physical
connection from other water supplies; no antifreeze or other additives of any
kind; all sprinkler drains discharge to atmosphere, dry wells, or other safe
outlets. These systems may or may not have fire department connections. Refer
to 310 CMR
22.22(9)(d)1.
|
X
|
X
|
X
|
A backflow prevention assembly does not have to be
installed on existing fire protection systems installed prior to March 21,
1997, provided that the fire protection system is registered with the public
water system, equipped with a UL listed alarm check valve that is properly
maintained in accordance with NFPA 25 and has not undergone substantial
modification defined within
310
CMR 22.22(9)(d)3. Alarm
check maintenance records must be available for inspection by the Department,
its designee or the public water system
|
|
(b) Class 2: Same as Class 1 except that booster
pumps may be installed in the connections from the street mains These systems
may or may not have fire department connections. Refer to
310
CMR
22.22(9)(a).
|
X
|
X
|
X
|
A backflow prevention assembly does not have to be
installed on existing fire protection system installed prior to March 21, 1997,
provided that the fire protection system is registered with the public water
system and equipped with a UL listed alarm check valve that is properly
maintained in accordance with NFPA 25. Alarm check maintenance records must be
available for inspection by the Department, its designee or the public water
system.
|
|
(c) Class 3: Direct connection from public water
system mains, plus one or more of the following: elevated storage tanks; fire
pumps taking suction from aboveground covered reservoirs, or tanks; and
pressure tanks.
|
X
|
X*
|
X*
|
*RPBP or DCVA contingent on evaluation of auxiliary
supply and on-site system in accordance with
310
CMR
22.22(9)(d)1.
|
|
(d) Class 4: Directly supplied from public water
system mains, similar to Class 1 and Class 2 with an auxiliary water supply
dedicated to fire department use and available to the premises, such as a
non-potable water source located within 1700 feet of the fire department
connection, (FDC).
|
X
|
X*
|
*RPBP on evaluation of auxiliary supply and onsite
system in accordance with
310
CMR
22.22(9)(d)1.
|
|
(e) Class 5: Directly supplied from public water
system mains, and interconnected with auxiliary supplies, such as pumps taking
suction from reservoirs exposed to contamination, or rivers and ponds; driven
wells; mills or other industrial water systems; or where antifreeze or other
additives are used.
|
X*
|
X*
|
*RPBP or air gap contingent on evaluation of
auxiliary supply and on-site system.
Refer to 310 CMR 22.22(9)(d)1.
|
|
(f) Class 6: Combined industrial and fire protection
systems supplied from the public water mains only, with or without gravity
storage or pump suction tanks.
|
X
|
X*
|
X
|
X
|
*RPBP contingent on evaluation of on-site water
system. Refer to
310
CMR 22.22
(9)(d)1.
|
|
(g) Residential fire protection systems for one and
two family detached dwellings and manufactured homes only. Fire protection
systems in three family dwellings meeting NFPA 13D requirements as provided in
780 CMR, Chapter 9, are included in this section.
|
X
|
X
|
X
|
Fire protection system in this category shall comply
with the requirements set forth in class 1 through 4 as
appropriate.
|
|
20. Solar Energy Systems
|
X
|
X
|
X*
|
Residential and small commercial having no chemicals
or only USP Glycine added to water
|
|
21. Single Jacketed Heat Exchangers
|
X
|
X
|
Each case should be evaluated
individually
|
Source of Table 8A is Department of Environmental Protection
(DEP)
310
CMR 22.22(c)
