This information is
provided by the University of Tennessee Municipal Technical Advisory
Service.
Title:
Drinking from a Fire Hydrant: The Fire Department's Role in Protecting
the Public Water System
Original Author:
West, Gary
Product Create
Date: 03/01/2006
Type:
Technical Bulletin
DRINKING FROM A FIRE HYDRANT
The Fire Department’s Role in Protecting the Public Water System
Gary L. West, MTAS Fire Management Consultant
A revised state regulation concerning fire hydrants is causing concern
for fire department leaders, providers of public water supplies, and
public health officials across the state of Tennessee. The new
regulation is the final result of the 1996 Amendments to the Safe
Drinking Water Act with the emphasis on contamination prevention. This
new regulation became effective in Tennessee on January 1, 2006.
The original rules in Tennessee were adopted in June 1974 and have
changed at least four times over the past 32 years. In the summer and
fall of 2005, as discussions and drafts of possible new regulations were
discussed, it became apparent that these rules would affect both public
health and public safety. On October 29, 2005, the Tennessee Department
of Environment and Conservation, Bureau of Environment–Division of Water
Supply, adopted the final version of the rules. The rules and
regulations are issued under the authority of Public Acts of 1983,
Chapter 324 where the Division of Water Supply is responsible for the
supervision of all public water systems. These new rules require all
communities having or installing water systems to be protected against
contamination and to properly identify and notify all fire departments
of fire hydrants that do not meet the minimum requirements. The purpose
of these rules and regulations is to provide guidelines for the
interpretation of T.C.A. § 68-221-701 et seq. and to set out the
procedures to be followed by the department in carrying out the state’s
primary enforcement responsibility under the Federal Safe Drinking Water
Act.
The rules apply to all public water supply systems that provide water
for human consumption through pipes or other constructed conveyances, if
such system has at least 15 service connections or regularly serves an
average of at least 25 individuals daily at least 60 days out of the
year.
According to the revised rule, Paragraph (18) of Rule 1200-5-1-.17
Operations and Maintenance is amended in its entirety and substitutes
the following so that as amended the paragraph shall read:
(18) All community water systems planning to or having installed
hydrants must protect the system from contamination. All water mains
designed for fire protection must be six inches or larger and be
able to provide 500 gallons per minute with 20 pounds per square
inch residual pressure. Fire hydrants shall not be installed on
water mains less than six inches in diameter or on water mains that
cannot produce 500 gpm at 20 psi residual pressure unless the tops
are painted red. Out of service hydrants shall have tops painted
black or covered with a black shroud or tape.
Existing Class C hydrants (hydrants unable to deliver a flow of 500
gpm at a residual pressure of 20 psi) shall have their tops painted
red by January 1, 2008.
The water system must provide notification by certified mail at
least once every five years beginning January 1, 2008, to each fire
department that has reason to utilize the hydrants, that hydrants
with tops painted red (Class C Hydrants) cannot be connected
directly to a pumper fire truck. Fire departments may be allowed to
fill booster tanks on any fire apparatus from an available hydrant
by using the water system’s available pressure only (fire pumps
shall not be engaged during refill operations from a Class C
hydrant).
A Matter of Public Health
Clean, safe drinking water is something we take for granted, but some
fire departments may unknowingly operate in a manner that would threaten
our public drinking water. Ensuring our water is safe is the
responsibility of everyone, including the fire department.
The cheapest, best, and most readily available extinguishing agent is
within one of those strategically placed fire hydrants which, of course,
is connected to the public water system as a convenient and effective
means to supply water for firefighting. Fire departments routinely
connect apparatus to fire hydrants and use the public water supply for
fire protection. Most fire apparatus are filled either at a fire hydrant
or in a fire station using the public water system. In fact, based on
the history, frequency of use, and availability of water from fire
hydrants, it would be unconscionable for a water provider to design a
public water supply without providing for the need for fire protection.
In recent years there has been much work done to improve water quality
in public water systems. Most of this work has been a result of federal
and state laws that have been enacted to ensure that the public water is
safe to drink. Congress passed the first legislation regulating drinking
water at the national level in 1974. The Safe Drinking Water Act
provided the basis for national requirements for water quality standards
and water supply operation. Tennessee has used this model to set state
regulations concerning public water systems. Probably the biggest areas
of concern have been cross connection and backpressure contamination.
In the residential setting, a cross connection is a direct link between
a household water line and a contaminated source such as a garden hose,
toilet tank or laundry tub. The most common contaminants, such as
pesticides, sewage and detergents, can enter the public drinking water
system through cross connections in home water lines. Hoses create most
household cross connections. Under certain conditions, the flow in
household water lines can reverse and siphon contaminants into the water
supply. For example, using a garden hose to spray pesticides is normally
harmless, but if the city's water supply is interrupted while you are
spraying, you may have a problem. If water main pressure is reduced due
to a water main break or nearby firefighting, a back siphonage effect is
created. This can draw water from the garden hose into the home water
supply. If you have a pesticide or fertilizer sprayer attached to your
garden hose, the chemicals can contaminate your water supply.
The public water system can also be contaminated by an effect called
backpressure. Backpressure results when the water supply is connected to
a system under high pressure, such as a hot water boiler for home
heating or a portable automobile pressure washer. Since the pressure in
these devices is higher than the normal home water supply, water can
sometimes be forced backwards. Contaminants in these systems, such as
cleaners or soaps in a pressure washer, can then enter and contaminate
the public drinking water supply.
During fire department operations, cross connections occur when a
residential hose or fire hose is submerged into the water tank when
filling a fire truck, when pulling the residual pressure too low on a
fire hydrant (below “0” psi), and even, in rare instances, when a fire
engine is being filled directly from a fire hydrant. These are only
three examples, but many more exist. Just like in the residential
setting, there is either a cross connection or backpressure problem that
causes the system to become contaminated.
So what does the fire department do? Let the house burn down or risk the
contamination of the water system? Either way it is a matter of public
health and safety, and it is a very difficult decision for any fire
officer to make.
These are very important issues and should be decided prior to
responding to a building on fire. A coordinated effort between the fire
department and the water utility is essential to protect public health
in these situations. In many cases, this cooperation hasn’t always
existed between the two departments. Issues related to locating fire
hydrants have caused problems in many communities for years. One problem
is locating fire hydrants strategically for fire department operations.
The fire department’s view is typically not the same as the water
utility’s view especially in allowing for water system flushing. Who has
the authority for properly locating fire hydrants? Different
jurisdictions have different interpretations of this question. The best
solutions occur when the fire department and water utility work together
on such issues.
By January 1, 2008, fire chiefs will be notified by certified mail that
certain fire hydrants cannot be used for firefighting. Most fire chiefs
would say that this is pretty strong, but in the event of an emergency,
decisions to use or not to use fire hydrants must be made. Who will
assume the liability at the time of a fire where a hydrant is available
but the fire department is not allowed to use it? Who will assume the
liability if the water system becomes contaminated? Water officials can
be held personally liable for knowingly allowing the system to become
contaminated. Many fire service leaders are saying this requirement is
too unreasonable especially in the event of a possible victim rescue.
In a recent discussion with the Tennessee Department of Environment and
Conservation (TDEC), I was told that the regulation change was intended
to improve the ability of a fire department to identify inadequate fire
hydrants. A previous Tennessee regulation did not follow the nationally
recognized standard for color coding of fire hydrants (NFPA 291). The
process of color coding allows the fire department to immediately know
the available water supply from a fire hydrant by its color markings. If
the water supply is limited or inadequate, the fire officer can make
immediate changes to fire suppression tactics. According to the TDEC
representative, a fire department can still use the fire hydrant to fill
the truck but cannot connect the truck to the fire hydrant with a direct
connection where a possible cross contamination could occur. A fire
department can, however, fill a dump tank from the hydrant and then pump
from the dump tank as long as there is an air gap between the hose
coming from the fire hydrant and the water in the dump tank. This seems
to be a lot of trouble, although necessary, to prevent pulling a vacuum
on an inadequate fire hydrant. It is already the policy of many fire
departments not to connect to Class C fire hydrants, and almost any
experienced fire commander would agree that it is dangerous to use these
limited flow hydrants.
Where main sizes, hydrant spacing, or distance from the water supply
contributes to the lack of available water supply for fire protection,
the fire department and the water provider should work together to
prepare a plan of corrections and a timetable to fix these problems.
So, can people actually get sick from the fire department connecting to
a Class C fire hydrant? Will this actually contaminate the water system?
According to several recognized articles by the federal Environmental
Protection Agency, there have been documented cases where water
contamination occurred due to something that a fire department did or
did not do. This type of contamination is quite difficult to pinpoint
although a backpressure situation could occur any time fire apparatus is
connected to almost any fire hydrant.
Most cases of waterborne disease outbreaks, have resulted in nausea,
diarrhea, and cramps; however, it is possible for some cases to result
in very serious illness and even death. Experts believe that most
waterborne disease outbreaks are not recognized, so in truth, there may
have been many times more than reported. According to the American Water
Works Association (AWWA), "Cross-connection contamination can provide an
opportunity for large amounts of biological material to enter the
distribution system. These events generally result in noticeable change
in water quality, including turbidity, increased content of solids, and
undesirable tastes and odors." However, in a report released by TDEC
entitled “Tennessee Rural Water Needs Report,” it states that only a
very small percentage (less than 1 percent) of the domestic water used
in a typical household is for drinking purposes. If contamination does
occur, there is only a small chance that people will be adversely
affected.
The other argument from fire officials is that fire departments seldom
connect hard suction hose to fire hydrants capable of causing a
backpressure in a water system. This was the old way of pumping water
from the hydrant. Today’s operation in most fire departments is
accomplished by laying 4-inch- or 5-inch-diameter hose (LDH) from the
hydrant to the emergency scene. An LDH operation is like laying a water
main from the hydrant to the fire scene using existing flows from the
hydrant at the present residual pressure. This hose is made of a soft
vinyl material and is not capable of being used for suction purposes.
The hose will simply collapse as the residual pressure is dropped.
Occasionally there could be a need for suction hose on a large fire but
most fire departments no longer even carry suction hose. The exceptions
to this are in rural areas where drafting from ponds and swimming pools
is necessary and in tanker shuttle operations where a fire engine is
used to draft from a dump tank. Regardless, using suction hose is a last
resort for most fire departments.
The time has come where a cooperative effort between fire departments
and water utilities is necessary. The need to provide required fire
flows with a goal to maintain good public health is paramount. Fire
hydrants must be properly marked and identified. The public also needs
to be educated in this area. If fire hydrants truly cannot be used, then
why not remove them? What happens to homeowners who have an insufficient
flow on the fire hydrant in front of their houses? Should they not be
notified also that the hydrant is inadequate? One thing is certain:
insurance requirements state that adequate water flows must be available
within 1,000 feet of structures to provide full credit for fire
hydrants. If not, insurance premiums will skyrocket.
Where fire hydrants are properly marked, most fire departments only
connect to a Class C hydrant as a last resort. The fire department needs
a reliable water source and according to Insurance Services Office (ISO)
on community water systems, a minimum of 500 gpm is needed to fight a
basic residential structure fire. Actually, depending on the distances
between structures, the necessary fire flow is much higher. ISO also
does not recognize hydrants on water mains less than six inches in
diameter. So, it has been known that connecting into a red top hydrant
will not supply basic needed fire flows and is only done as a last
resort. However, ISO will recognize a fire hydrant in a rural setting
where tanker shuttles are necessary that have a minimum flow of 250 gpm
and a residual pressure of 20 psi.
This new rule should actually benefit fire departments by alerting them
to the locations of unreliable (Class C) fire hydrants. The fire
department should identify areas where red top hydrants exist and
request reliable and appropriately sized water lines be provided that
supply the needed fire flow. The ideal situation is where the water
supply system is originally built to meet needed flow requirements. Many
times this needed amount cannot be obtained from a single hydrant or
single water distribution line. Alternatives include looping of multiple
sources as needed as well as multiple hydrants. Buildings should be
designed to determine needed fire flows. Hydrants should be flow tested
and maintained in accordance with AWWA standards.
In actuality, the fire service should recommend that the rule become
stricter by requiring all hydrants to be color coded to National Fire
Protection Association (NFPA) standard colors.
Two things fire departments should do immediately are to get correct ISO
hydrant flows on all hydrants, and second, make sure all hydrants are
adequately marked and color coded. When this is done, risk assessments
and preplanning should be conducted in areas where inadequate flows are
available. Alternative water sources can then be used or the water
system improved to meet basic standards. Providing tanker shuttles
becomes very expensive but may be an alternative to inadequate public
water supplies.
Fire Hydrants—Today and Tomorrow
The first thing to consider is that fire hydrants that are inadequate
for firefighting today have probably always been inadequate for
firefighting. So why were they installed inadequately?
Water systems are expensive and fire hydrants are required by state
planning regulations. Needed fire flows are not always available during
the design phase of a water system project. Many other factors help
determine actual flows and water main sizes to certain areas. Fire
hydrants are also used to flush public water systems and many hydrants
have been installed solely for this purpose. Nevertheless, inadequate
and unmarked fire hydrants provide a false sense of security to fire
departments and property owners.
Marking of Fire Hydrants
To effectively fight a fire, firefighters must be able to determine
hydrant flows immediately upon arrival. Fire hydrants should be color
coded to the NFPA 291 standard so that firefighters can immediately have
a visual indication of hydrant flow. Otherwise, without color coding
they won’t have any idea of a hydrant’s flow potential.
NFPA 291 Marking of Fire Hydrants says that fire hydrant bonnets and
caps shall be coded as follows:
COLOR
|
CLASS
|
AVAILABLE FLOW@ 20 psi residual
|
BLUE
|
AA
|
1500 GPM or more
|
GREEN
|
A
|
1000-1499 GPM
|
ORANGE
|
B
|
500-999 GPM
|
RED
|
C
|
Below 500 GPM
|
Fire hydrants should be immediately recognizable to firefighting forces
as well as to the general public. The NFPA specifies that fire hydrants
are to be painted chrome yellow; however, it accepts other body colors
that were already in use at the time the standard was adopted in the
1970s. Other highly visible colors that have been used include white,
bright red, chrome silver, and lime yellow. In jurisdictions where no
standard color has been established, the most important aspect is
consistency. Standard colors should be adopted that, preferably, are the
same throughout the region.
NFPA also recognizes that there often are functional differences in
service provided by municipal and private hydrant systems. Therefore,
NFPA specifies that nonmunicipal hydrants be painted a color that
distinguishes them from municipal hydrants. Violet has been established
as the international color code for nonpotable water. Therefore hydrants
supplied by nonpotable sources should be painted violet (light purple).
The following body colors are recommended for fire hydrants:
Supply |
Body Color |
Municipal System
|
Chrome Yellow
|
Private System
|
Red
|
Nonpotable System
|
Violet (Light Purple)
|
One of the biggest mistakes made in color coding a hydrant is the
failure to reduce the residual flow pressure to 20 psi. Many departments
will color code the hydrant at whatever the flow was without taking time
to chart or calculate the actual flow at 20 psi. This requires extra
work but can mean the difference in color coding up to 50 percent of the
hydrants in a given system.
How to Properly Flow Test a Fire Hydrant
Many fire departments and water utilities don’t know how to properly
flow a fire hydrant. According to TDEC, there is not a state regulation
on how to properly flow a fire hydrant; however, they do recognize the
American Water Works Association pamphlet No. M-17 as the recognized
standard. This pamphlet is also what both ISO and NFPA recognize as the
approved method for flowing fire hydrants.
According to this standard, the proper way to test a hydrant and water
main is to put a cap gauge on the test hydrant and take a static
reading. Then proceed downstream to the next flow hydrant and back
upstream to the closest flow hydrant and flow both at the same time. Use
as many ports and sizes of discharges to make the largest drop in
residual pressure. Pitot each flowing port and then record the residual
pressure back at the test hydrant.
When the test is complete, you will use three pieces of data to
determine the flow of the hydrant: the static pressure, the residual
pressure, and the flow pressure, which will be converted to gallon per
minute by using a calculator or flow chart. The residual pressure will
need to be charted to record the flow in gpm at 20 psi. According to
water experts, this way of flow testing a fire hydrant is the best and
most accurate method. Doing single hydrant flow tests is one reason so
many communities seem to have so many red top hydrants.
Conclusion
Fire departments and water providers in Tennessee have come a long way
over the past several years. Both groups now recognize that they
contribute to the economic development and stability of the communities
they serve. With the willingness to work together, each industry needs
to strive to understand the responsibilities to the public and the needs
of the other, without reservations. Neither sector is more important
than the other. Both serve to protect the health and safety of the
public; both must do so without undermining or disregarding each other
or any other health and safety agency. The water industry has a
responsibility to provide safe drinking water to all consumers served by
public water supplies. The fire department has a responsibility to fight
fires.
Yes, we all do drink from fire hydrants, and fire departments do have a
responsibility for keeping our drinking water as safe as possible. Water
providers have an equal responsibility to provide the needed fire flows
for the types of structures that are being built in various parts of the
community. Everyone can benefit from this cooperative effort with
reasonable water rates and lower insurance premiums where adequate water
supplies are available and the fire department is trained to make safe
connections to the water system. |