HomeMy Public PortalAbout2003.02.14 SRF DW Loan 9906 - Loan CloseoutSTATE OF IDAHO
DEPARTMENT OF
ENVIRONMENTAL QUALITY
RECEIVED FEB 2 4 2003
1445 North Orchard • Boise, Idaho 83706-2239 • (208) 373-0550 Dirk Kempthorne, Governor
C. Stephen Allred, Director
February 14, 2003
Mr. Robert Strope
City Manager
P.O. Box 986
McCall, ID 83638
RE: City of McCall Water Treatment Plant
SRF DW Loan 9906 - Loan Closeout
Dear Mr. Strope:
The Loan Offer, Acceptance, and Contract (Contract) explains City requirements. Some of the conditions
are self -certifying or ongoing. Listed below are the remaining items that DEQ must review and approve
prior to loan closeout.
1. Final approval of all Change Orders. I am working with Brad Bjerke of Donohue & Associates on
those.
2. Final Pay Request.
3. User Charge System and Water System Protection Ordinance. These two documents are listed in
two places in the Contract and I believe there was some confusion about that when the City
provided the schedule in the Contract. "Enacted" refers to the approved City ordinance, which I
presume was what you meant when you listed them as completed. "Approved" refers to DEQ
approval. Please complete as much of the attached checklist as possible and forward the checklist
and those two documents for review and approval. I will review the documents and sign the
checklist, then issue the approval when appropriate.
4. Operation and Maintenance Manual. Ginny Carol of Donohue & Associates will be submitting
that document and the associated checklist in the next week or so.
5. Certification of filtration performance according the DEQ guidance. Ginny Carol of Donohue &
Associates will be submitting that information for review and approval in the next week or so.
Please call me with any questions at 373-0560 or via e-mail at mmarchus@deq.state.id.us.
Sincerely,
Monty G. Marchus, P.E.
Staff Engineer
MGM:ve: H:\MCCALL\SRF Loan\Loan Close-out-1.doc
Enclosure: Drinking Water Loan Account Checklist For User Charge System (UCS)
And Water System Protection Ordinance Review
cc: Bill Jerrel, DEQ -State Office
Jack Gantz, DEQ -Boise Regional Office
Brad Bjerke, P.E., Donohue & Associates
Reading file, Source file #13.5, Manager's file
CHAPTER 7
Attachment A
DRINKING WATER LOAN ACCOUNT
CHECKLIST FOR USER CHARGE SYSTEM (UCS)
AND WATER SYSTEM PROTECTION ORDINANCE REVIEW
Project Name Project No.
Reviewer Date
Yes/Adequate - Y
CHAPT7-A
No/Inadequate - N Not Applicable - N/A
1. Does the breakout of anticipated receipts include the necessary
items to determine the source of funds, and are the funds sufficient
to adequately maintain the system?
2. Does the budget reflect adequate expenditures for all necessary
items such as salaries, power, chemicals, maintenance, water
testing, debt service and equipment replacement needed to
maintain and operate the system throughout its design life?
3. Does the UCS have a requirement for review at least biennially
and a provision to revise rates accordingly?
4. Does the UCS distribute costs among users in an equitable
manner?
5. Does the UCS provide for annual notification to each user about
the distribution of charges and costs?
6. If there is more than one political jurisdiction within the service area
controlling water service, answer the following:
a. Has each jurisdiction adopted a compatible UCS?
b. Have intermunicipal agreements been approved?
7. Does the UCS state the basis of the system?
8. Were estimated user costs discussed during the engineering report
hearing? If not, was a separate hearing on costs and affordability
held?
7A-1
Rev8/01
9. Is UCS incorporated in an approvable draft enacting document
(generally an ordinance for a City or a resolution for a Water
District)?
10. Does the WSPO include or refer to a standard set of specifications
for water system mains, service connections, and service lines and
proper construction, testing, and disinfection of them?
11. Does the WSPO require inspection of water system connections
and service lines prior to burying?
12. Does the WSPO provide for fines or other penalties for
individuals who purposely or knowingly inject or otherwise place
hazardous or harmful substances into the water system?
13. Does the WSPO provide a cross connection control program
which adequately requires installation of devices or assemblies,
yearly testing, and a tracking and notification system for testing?
14. Is final enactment of UCS and WSPO scheduled before
completion of the loan project?
COMMENTS:
CHAPT7-A
7A-2
Rev8/01
STATE OF IDAHO
DEPARTMENT OF
ENVIRONMENTAL QUALITY
1445 North Orchard • Boise. Idaho 83706-2239 • (208) 373-0550
February 20, 2003
Mr. Robert Strope
City Manager
216 E. Park
McCall, ID 83638
RE: City of McCall Water Treatment Plant
Dear Mr. Strope:
RECEIVED i ) 2 •
Dirk Kempthorne. Governor
C. Stephen Allred, Director
The Idaho Rules for Public Drinking Water Systems § 550.07 requires that "All suppliers of
water for community water systems shall implement a cross connection control program to
prevent the entrance of toxic or hazardous substances to the system." The Idaho Department of
Environmental Quality (DEQ) SRF loan offer has a similar requirement.
To assist you in meeting this requirement, we have attached the following items to this letter.
• Applicable sections from the Idaho Rules for Public Drinking Water Systems.
• Questions and Answers About Cross -Connection Control
• Cross Connection Model Ordinance (from the State of Washington)
• An example of a draft Ordinance (should be converted to Resolution or equivalent for a
homeowner's association) used by an Idaho municipality and homeowner's association.
• Backflow Prevention Cross Connection Control Handbook. This simple pamphlet was
approved by FEBCO for redistribution. Note that the DEQ recommended reference is the
Accepted Procedure and Practice in Cross Connection Control Manual — Pacific Northwest
Section — American Waterworks Association, current edition.
• Backflow Prevention Assemblies Approved for Installation in the State Of Washington (DEQ
adopted Washington's list)
All installations should be viewed and permitted by the state Plumbing Bureau.
Also required is a draft form that would be used in an actively operated, cross connection control
program. The form would cover items such as:
• list of customers,
• potential cross connections and control devices used for each one
ed
on Recycled
Pape
Mr. Robert Strope
City Manager
February 20, 2003
Page 2
• verification that each device was on the current DEQ approved list when it was installed,
• last date the device was tested (at least yearly testing) by a state certified tester, and the
tester's name.
Please call me with any questions at 373-0560 or via e-mail at mmarchus@deq.state.id.us.
Sincerely,
Monty G. Marchus, P.E.
Staff Engineer
MGM:ve: H:\MCCALL\SRF Loan\CCC Program.doc
Enclosures
cc: Bill Keating, City of McCall
Brad Bjerke, Donahue Associates
Reading file, Source file #13..3, Manager's file
r
Oct 07 02 02:51p DEQ
STATE OF IDAHO
DEPARTMENT OF
ENVIRONMENTAL QUALITY
2087691404 p.1
Post -IC Fax Note 7671
To
Co/Dept. t'': l '
Phone #
Fax
2110 Ironwood Parkway • Coeur d'Alene, Idaho 83814-2648 . (208) 769-1422
September 4, 2002
Barbara Bentley, Secretary
Cottonwood Point Water & Sewer Assn, Inc.
PO Box 708
St. Maries, ID 83861
Dare
From
Co.
Phone #
Fax R
EA1C-ROW
;J -(pages" /1
Dirk Kcmpthorne, Governor
Dn Allred, Director
OCT 0 7 2002
DEPARTMENT OF
RE: Cross Connection Control Program ENVIRONMENTAL QUALITY
BOISE REGIONAL OFFICE
Dear Ms. Bentley:
This letter is a response to the draft cross connection control ordinance that you asked me to review. The
document appears to be complete and will meet DEQ's requirements for a cross connection control
program. Below are the comments and suggestions on the document based on my review:
1. The term "Ordinance" may not be correct in this setting. Typically, the term "Ordinance" is used
for documents produced by municipalities and other government bodies. As your system is not
controlled by a municipality, the term "Resolution" may be more appropriate. This would make
the title of the document, "A Resolution of the Cottonwood Point Water & Sewer Assn, Inc..."
2. You may want to change the definition of a cross connection, section 3.4, to match the definition
in the Idaho Rules for Public Drinking Water Systems:
Cross Connection. Any actual or potential connection or piping arrangement between a public or
a consumer's potable water system and any other source or system through which it is possible
to introduce into any part of the potable water system used water, water from any source other
than an approved public water system. industrial fluid, gas or substance other than the intended
potable water with which the system is supplied Cross connections include bypass
arrangements, jumper connections, removable sections, swivel or change -over devices and other
temporary or permanent devices which, or because of which, "backflow" can or may occur.
3. In response to your question about publishing in a newspaper, DEQ will not require that this
document be published. From DEQ's perspective, this is not an item that requires an official
public notice. You may inform the system users as you see fit.
Thank you for giving us the opportunity to comment on your proposed cross connection control program.
We appreciate the willingness of the Cottonwood Point Water & Sewer Association, Inc. to comply with
the Idaho Rules for Public Drinking Water Systems. Please provide us with a copy of the final version of
the resolution when it becomes effective. If you have any further questions, please do not hesitate to call
me at (208) 769-1422.
Sincerely,
Daniel G. Remmick, E.I.T.
C: Steve Tanner, DEQ -CDA
Oct 07 02 02:51p DEQ
COTTONWOOD POINT
WATER & SEWER ASSOCIATION, INC.
P.O. BOX 708
ST. MARIES, IDAHO 8386:
Daniel G. Remmick, E.I.T.
Department of Environmental Quality
2110 Ironwood Parkway
Coeur d ' Alene, ID 83814-2648
Dear Mr. Remmick, E.I.T.,
2087691404 p.2
August 22, 2002
I FJV E,
AUG 2 7 2002
RE: Sanitary Survey PWS # 1050008
This letter is to respond to our sanitary survey of June 7, 2002. Please
note the PWS number listed on your report is incorrect. Please note our correct
PWS number is listed above.
All deficiencies have been corrected as follows:
1. We have obtained a new chlorinator test kit from the Hach Company.
It is test kit, CH -66F Free Chlorine catalog 223102, purchased from the
Internet as you advised, purchase price with delivery and tax was
$49.90. We are currently adjusting our chlorine level to obtain the
desired .2 PPM in the distribution locations.
2. Enclosed is a draft copy of our cross connection control ordinance,
which will be brought before the board for implementation at our next
annual meeting. Is it necessary to have this published in the paper?
Please note page six, indicated that fact. Could this ordinance be
handed out or mail delivered to users and lot owners instead of
publication? Please review the draft copy and let me know of any
changes. We anticipate having the cross connection control program
in place before December 31, 2002.
3 An atmospheric vacuum breaker was installed on the hose bib at the
wellhous: to eliminate any cross connection.
4. The vent on the well was screened with a # 24 stainless steel mesh
and the electrical conduit was sealed with the addition of a clamp.
Please contact me if further information is needed on any of the above items. I
would appreciate your commenting on the Cross -Connection Ordinance.
Thank you.
Enclosure (1)
bb
Si) terely,
Barbara Bentley
Secretary
Oct 07 02 02:52p DEQ 2087691404 p.3
Draft
August 22, 2002
PROVIDING FOR THE ESTABLISHMENT OF A WATER SYSTEM CROSS CONNECTION
POLICY FOR THE
PROVIDING FOR A TITLE; PROVIDING FOR THE PURPOSE Ai,. SCOrr.; rrJV1D1NG
FOR DEFINITIONS; PROVIDING FOR UNLAWFUL CONTAMINATION OR CROSS
CONNECTIONS; PROVIDING FOR PROTECTION OF WATER SUPPLY; PROVIDING FOR
USE OF BACKFLOW PREVENTION DEVICES; PROVIDING FOR CROSS CONNECTION
INSPECTIONS; PROVIDING FOR THE TYPE OF PROTECTIVE DEVICES REQUIRED;
PROVIDING FOR VIOLATIONS ANI) PENALTIES, MCI AIDING MISDEMEANOR
CRIMINAL PENALTIES; PROVIDING FOR SEVERABILITY; AND PROVIDING THAT
THE ORDINANCE WILL BE EFFECTIVE UPON PUBLICATION.
RP IT ORDAINED. RV THF, BOARD OF DIRECTORS
SECTION 1. TITLE
This
Connectior
shall be known as tL:_
ass
SECTION 2. PURPOSE AND SCOPE:
The purpose of this is to protect the public health of water consutners by the control of
actual and/or potential cross connections.
SECTION 3. DEFINITIONS:
As used in this ordinance, unless the context otherwise requires, the following words and terms
shall have the meanings ascribed to them in this Section:
3.1. BACKFLOW: The flow, other than the intended direction of flow, of any foreign liquids,
gases or substances into the distribution system of a public water supply as a result of reduced or
reversed pressure.
3.2 BACKFLOW PREVENTION DEVICE: A device which, when properly installed between
the Cottonwood Point water supply system and the terminus or point of ultimate use, will prevent
backflow.
3.3 CONTAMINATION: The entry into or presence in a public water supply of any substance,
which may be delet;rious to health and/or quality of the water.
Page 1 of 6
Oct 07 02 02:53p DEQ 2087691404 p.4
Draf.
August 22, 2002
(hove 40
II I D �4%✓ Yor id;::
3.4 CROSS CONNECTION: Any physical arrangement whereby a public water supply idf/ jj/e/ ni
is connected, directly or indirectly, with any other water supply system, sewer, drain,
conduit, pool, storage reservoir, plwnbing fixture or other device which contains or may 4 CI^'
containcontaminated water, sewage or other waste or liquids of unknown or unsafe gy jtemr
quality which may be capable of imparting contamination to the public water supply as a
result of backflow.
3.5 PUBLIC WATER SUPPLY- Any system of water supply intended or used for
human consumption or other domestic uses, including source, treatment, storage,
transmission and distribution facilities, where water is furnished to any collection or
ncunber of individuals or is made available to the public for human consumption or
domestic use.
SECTION 4. UNLAWFUL CONTAMINATION OR CROSS CONNECTIONS:
It is unlawful for the owner, tenant, occupant, lessee or other use:
water to introduce or permit the introduction of pollution or contamination of any kind
into thr is unlawful for any person to install
or maintain any cross connection-
SECTION 5. PROTECTION OF WATER SUPPLY:
No water service connection to any premises shall be installed or continued in use by the
. unless the water supply is protected by
backflow prevention devices whenever required by this .r by rules or
standards adopted by the State of Idaho. The installation or maintenance of a cross
connection which will endanger the water quality of the potable water supply of
shall be unlawful and is prohibited and shall be penalized as
hereinafter provided. The control or elimination of the cross connections shall be in
accordance with this and the latest edition of appropriate manuals of standard
practice pertaining to the cross connection control approved by the State. (Or
regulations set down in IDAPA 16.01.08601,04.a, together with the latest edition of
appropriate manuals of standard practice pertaining to cross connection control.
SECTION 6. USE OF BACKFLOW PREVENTION DEVICES:
Backflow prevention devices shall be installed by the property owner, tenant, occupant,
lessee or other user of ` water where the nature and extent of the
activities conducted or materials used or stored on the premises would present an
immediate and da•. gerous hazard to health and/or be deleterious to the quality of the
Page 2 of 6
Oct 07 02 02:53p DEQ
Draft
2087691404 P•5
August 22, 2002
Should a cross connection occur, even though such
cross connection does not exist at present, a backflow prevention device shall be
installed under circumstances including, but not limited to, the following:
6.1 Premises having an auxiliary water supply, unless the quality of the auxiliary supply is
acceptable to the
6.2. Premises having internal cross connections that are not correctable, or intricate
plumbing arrangements, which make it, impracticable to ascertain whether or not cross
connections exist.
6.3 Premises where entry is restricted so that inspections for cross connections cannot be
made with sufficient frequency or at sufficiently short notice that cross connections does
not exist.
6.4 Premises having a repeated history of cross connections being established or
reestablished.
6.5 Premises on which any substance is handled under pressure so as to permit entry
into thc public water supply or where a cross connection could reasonably be expected
to occur. This shall include the handling of process waters and cooling waters.
6.6 Premises having pumps or pumping devices, which my affect the pressure within
any line connected to the
6.7 Premise! where materials of a toxic or hazardous nature are handled in such a
manner that if back siphonage should occur; a serious health hazard might
result.
6.8 Other premises as determined by
the rules established by the State of Idaho. wherc backflow prevention devices
are required to protect thc public water supply.
SECTION 7. CROSS CONNECTION INSPECTIONS:
Upon passage of this , all existing buildings, structures ur improvements of
any nature now receiving water through the . /ill be
inspected by thc for thc purpose of ascertaining
whether cross connections exist.
Pagc 3 of 6
Oct 07 02 02:54p DEQ 2087691404 P-6
Draft
August 22, 2002
7.1 ]f hacktlow prevention devices arc found to be necessary, the property owncr shall
have thc required device installed ar' ;nspected within a period of three (3) months
following the date of notification Upon
installation of such a device, property owners will be required to hire a licensed,
American Waterworks Association (AWWA) certified tester to inspect the backflow
prevention device. Within 30 days of the date of the inspection, the AWWA licensed
tester, or property owner, must submit, in writing, the results of this test to the
7.2. Subsequently, all existing buildings, structures or improvements of any nature,
after having a backflow prevention device installed, and still receiving water through
the .... will be required to have annual inspections by
an AWWA licensed tester, and provide results of the inspection within 30 days of the
inspection dale
7.3. Whenever the backflow prevention devices are found to be defective they shall be
repaired, overhauled or replaced at the customer's expense, within no more than 30
days of the datc of inspection.
7.4. No water shall be delivered to any structure hereafter built within the
or within areas serves' until the
same shall have been inspected ' • for
possible cross connections and have been approved as being free of the same.
7.5 Any structure hereafter built within the _«- " :.Wafgror within areas
served • ing backflow prevention devices will
adhere to the same rules as set ,.I� at su . cctions 7.1, 7.2 and 7.').
SECTION 8. TYPE OF PROTECTIVE DEVICES REQUIRIED.
The type of protective device required shall depend on the degree of hazard that exists.
8.1 Backflow prevention devices required by thc : hall be in accordance with
the types of devices specified in the latest edition of appropriate manuals of
standard practice pertaining to the cross connection control approved by the
State.
8.2. An air -gap separation or a reduced pressure principle backflow prevention device
shall be installed where the public water supply may be contaminated with sewage
Page 4 of 6
" U C L U 1 U L , ( ) U . ' 4
D r a f t
2 0 8 7 6 9 1 4 0 4 P . 7
A u g u s t 2 2 , 2 0 0 2
i n d u s t r i a l w a s t e o f a t o x i c n a t u r e o r o t h e r c o n t a m i n a n t w h i c h c o u l d c a u s e a h e a l t h o r
s y s t e m h a z a r d .
8 . 3 . I n t h e c a s e o f a s u b s t a n c e w h i c h m a y b e o b j e c t i o n a b l e b u t n o t h a z a r d o u s t o h e a l t h ,
a d o u b l e c h e c k v a l v e a s s e m b l y , a i r - g a p s e p a r a t i o n o r a r e d u c e d p r e s s u r e p r i n c i p l e
b a c k f l o w p r e v e n t i o n d e v i c e s h a l l h e i n s t a l l e d ,
R . 4 B a c k f l o w p r e v e n t i o n d e v i c e s r e q u i r e d b y t h i s s h a l l b e i n s t a l l e d a t t h e
m e t e r , a t t h e p r o p e r t y l i n e o f t h e p r e m i s e s w h e n m e t e r s a r e n o t u s e d o r a t a l o c a t i o n
d e s i g n a t e d T h e d e v i c e s h a l l b c l o c a t e d s o
a s t o b e r e a d i l y a c c e s s i b l e f o r m a i n t e n a n c e a n d t e s t i n g a n d f u r t h e r m o r e , w h e r e n o p a r t o f
t h e d e v i c e w i l l b e s u b m e r g e d .
8 . 5 N o u n d e r g r o u n d s p r i n k l i n g d e v i c e w i l l b e i n s t a l l e d w i t h o u t a d e q u a t e b a c k t l o w
p r e v e n t i o n d e v i c e s a t t h e p o i n t f r o m w h i c h t h c w a t e r f o r i r r i g a t i o n i s t a k e n f r o m t h e
p u b l i c w a t e r s u p p l y . S u c h s p r i n k l e r l i n e s s h a l l b e c o n n e c t e d o n l y t o m e t e r e d p r i v a t e
w a t e r s e r v i c e l i n e s .
S E C T I O N 9 . V I O L A T I O N S A N D P E N A L T I E S :
i f a c u s t o m e r f a i l s t o c o o p e r a t e i n t h e i n s t a l l a t i o n , m a i n t e n a n c e , t e s t i n g , r e p a i r o r
i n s p e c t i o n o f b a c k f l o w p r e v e n t i o n d e v i c e s r e q u i r e d b y t h i s t h e n d e l i v e r y
o f w a t e r t o t h e p r o p e r t y m a y b e d i s c o n t i n u e d u n t i l t h e d e f i c i e n c y i s c o r r e c t e d t o t h e
' s f a c t i o n . D e l i v e r y o f w a t e r t o t h e
p r o p e r t y m a y a l s o b e d i s c o n t i n u e d i n t h e e v e n t a n i m p r o p e r c r o s s c o n n c c t i o n i s n o t
c o r r e c t e d b y a c u s t o m e r w i t h i n t h e t i m e l i m i t s s e t b y t h i s o r d i n a n c e . I f
c o n t a m i n a t i o , c u r s a s a
c o n s e q u e n c e o f a s y s t e m u s e r f a i l i n g t o c o m p l y w i t h p r o v i s i o n s o f t h i : t h c
u s e r s h a l l b c r e s p o n s i b l e f o r a l l c o s t s o f d e c o n t a m i n a t i o n a n d r e m e d i a t i o n o f t h e
d a m a g e c a u s e d t h e r e b y . S u c h v i o l a t i o n s h a l l a l s o b e s u b j e c t t o m i s d e m e a n o r
c r i m i n a l p e n a l t i e s i n c l u d i n g a f i n e o f u p t o $ 3 0 0 p e r d a y a n d i n c a r c e r a t i o n f o r u p t o
s i x ( 6 ) m o n t h s f o r c a c h v i o l a t i o n . E a c h d a y o f n o n c o m p l i a n c e m a y b e c o n s i d e r e d a
s e p a r a t e v i o l a t i o n .
S E C T I O N 1 0 . S E V E R A B I L I T Y :
T h e p r o v i s i o n s o f t h e a r e h e r e b y d e c l a r e d t o h e s e v e r a b l e a n d i f a n y
p r o v i s i o n t o a p e r s o n o r c i r c u m s t a n c e i s d e c l a r e d i n v a l i d f o r a n y r e a s o n , s u c h
d e c l a r a t i o n s h a l l n o t a f f e c t t h e v a l i d i t y o f r e m a i n i n g p o r t i o n s
S E C T I O N I I . E F F I C T I V E D A T E :
P a g e 5 o f 6
Oct 07 02 02:56p DEQ
Draft
2087691404 p.8
August 22, 2002
This ' --•: shall take effect and be in full force upon its passage, approval and
publication ofa summary in one (1) issue of the Gazette Record, as newspaper of
general circulation in the
anu the official newspaper
PASSED under suspension of rules upon which a roll call vote was duly taken, this ordinance
was duly enacted . at a regular
meeting of the Board of Directors on the day of
2,002.
APPROVED by the President, this
ATI -EST:
By:
day of
2002.
Page 6 oP 6
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BACKFLOW PREVENTION
,••
Contents •
Page
Backflow—What is it? 1
Case Histories 2 - 3
Typical Cross Connections 4 - 5
Backflow Prevention Devices 6
How Backflow Prevention Devices Work 7
Device Selection 8
Installation 8 - 9
Testing 9
Bibliography
"Cross -Connection Control
Manual" (EPA -570/9-89-007)
U.S. Environmental Protection
Agency, Water Supply Division,
Washington D.C. (1973)
Recommended Practice for
Backflow Prevention and
Cross -Connection Control,
AWWA M14, American Water
Works Association, Denver,
CO, 1990.
"Manual of Cross -Connection
Control," Foundation for
Cross -Connection Control and
Hydraulic Research, University
of Southem Califomia;
Los Angeles, Calif. 90007
American Society of Sanitary
Engineering (ASSE), Profes-
sional Qualification Standards,
Backflow Prevention Assem-
blies - Series 5000, Bay Village,
Ohio.
Canadian Standards Associa-
tion, Manual for Selection,
Installation, and Field Testing,
Can/CSA-B64.10-95
A Brief History of
Cross Connection
Control
Man has long recognized the
need for pure drinking water,
but only in the last 50 or 60
years has there been any real
effort to prevent contamination
caused by cross connections.
Although double check valves
came into use around the turn
of the century to isolate fire
mains and industrial water lines
from the potable water supply,
little interest was shown in the
individual treatment of
plumbing fixtures.
In 1929 the major breakthrough
came when a device consisting
of two check valves with a relief
valve between them was
successfully tested in Danville,
Illinois. However, this valve was
not produced commercially and
it was not until the late 1930's
that the real development of
effective vacuum breakers and
backflow preventers took place.
It was in this period that
ordinances for cross connec-
tion control began to be
enforced. The Safe Drinking
Water Act, signed into law by
President Ford, placed more
emphasis on the responsibility
for drinking water protection.
The need for cross connection
control exists in all types of
premises, whether industrial or
residential. Backflow prevention
devices help protect the public
safety by preventing potable
water contamination in such
critical areas as municipal
water systems, food processing
plants, medical and dental
water supplies, and many
industrial applications.
An informative booklet,
for the purpose of a better
dissemination of the facts
about potential hazards to
public health through back-
flow contamination.
Copyright 1997
Backflow...
What is it?
Backflow? You may have heard
of it, and you may understand
some of what it involves. This
booklet will help you to
understand it better; exactly
what it is, and how to prevent it.
Backflow is the undesirable
reversal of the flow of water or
mixtures of water and other
undersirable substances from
any source (such as used
water, industrial fluids, gasses,
or any substance other than the
intended potable water) into the
distribution pipes of the potable
water system. There are two
types of backflow conditions:
backpressure and backsiphon-
age.
Backpressure: Occurs when
the user system is at a higher
pressure than the supply water
systems allowing undesirable
substances to be "pushed" back
into the potable water system.
Some causes are: booster
pumps, potable water system
connections for boilers,
interconnections with other
piping systems operating at
higher pressures, or higher
elevations in user systems
such as high-rise buildings.
One specific example of this
would be a steam heating
system with the make-up water
line piped directly into the
boiler. The higher pressure in
the boiler could force the
chemically treated boiler water
back through the make-up
water line and into the potable
water system.
Backsiphonage: Occurs when
negative or reduced pressure
exists in the supply piping
allowing undesirable substances
to be "drawn" into the potable
water supply. Some causes are:
undersized supply piping,
supply line breaks, reduced
supply system pressure on the
suction side of an on-line
booster pump, or sudden
upstream high demand. An
example of this is a child
drinking milk with a straw. The
child "sucks" on the straw and
the milk flows up the straw and
into the child's mouth. What the
child is actually doing is
creating a subatmospheric
pressure in his mouth and the
atmospheric pressure (14.7
psia at sea level) is pushing
down on the surface of the milk
and forcing the milk up the
straw and into the child's mouth.
There is one other very
important term that must be
understood before we can
proceed. The term is "Cross
Connection" and it is defined as
any actual or;potential
connection between a potable
water system and any other
source or system through
which it is possible to introduce
into the potable system any
used water, industrial fluid, gas,
or other substance other than
the intended potable water with
which the system is supplied.
By-pass arrangements, jumper
connections, removable
sections, swivel or change -over
devices and other permanent
or temporary devices through
which, or because of which,
backflow can or may occur are
considered to be cross
connections.
City Water
a
Make-up -
Water Line
Case Histories
"All of this is very interesting,
but does it REALLY happen?"
you may ask. The answer to
that is an emphatic YES! Below
are listed some typical cases of
backflow that actually occurred.
Case No. 1
The year was 1933. People
from all over the world were
crowding into one of America's
largest cities to see the
"World's Fair." An epidemic of
Amoebic Dysentery broke out
and official records show that
98 people died and 1,409
others became seriously ill.
Hundreds, possibly thousands
of other affected people were
never counted by investigating
agencies since when they
became ill, they went home. A
special investigating committee
of public health authorities
found the main reason of this
catastrophe to be "...old and
generally defective plumbing
and cross connections
potentially permitting
backsiphonage from fixtures,
such as bathtubs and toilets..."
Case No. 2
In December, 1964, a hospital
in the State of Michigan had its
potable water system contami-
nated. The cause was an
unprotected autopsy table in
the hospital's morgue.
2
Case No. 3
It was in July of 1955 in San
Pedro, California, a U.S. Navy
Destroyer pumped salt water
through five obsolete check
valves into the street mains in a
90 square block of the town.
Case No. 4
This unusual death was caused
by backsiphonage in a suburb
of one of California's largest
cities. A man was spraying his
lawn with a commercial weed
killer that contained an arsenic
compound. His applicator was
an aspirator device on his
garden hose, to which was
attached a bottle of the arsenic
poison. When he had finished
spraying, the man turned off
the hose, disconnected the
applicator, and since it was a
warm day, turned the hose on
again to get a drink of water. A
short time later, he was dead
from arsenic poisoning. At
some time while he was
spraying, a backsiphonage
condition had occurred and the
arsenic was carried back into
the hose.
Case No. 5
In 1969 in Utah, raw irrigation
water was pumped through a
farm standby irrigation
connection into over half of the
entire town's potable water
system. The standby connec-
tion was not protected with a
backflow prevention device.
Case Histories
Case No. 6
In August, 1969, 83 football
team members and coaching
staff were stricken with
infectious hepatitis due to
subsurface hose bibs and a
nearby fire. The fire trucks in
fighting the fire reduced the
main pressure enough to
cause backsiphonage from
the hose bibs.
Case No. 7
In the summer of 1970 in New
Jersey, a soft drink vending
machine in the Caddy house of
a golf club was connected to
the building heating system in
which hexavalent chromium
had been added. Eleven cases
of nausea were reported by the
caddies.
1
MIL
Heating System
Line Treated with a
Hexavalent Chromium
3
Typical
Cross Connections
Spray Hose In Sink
This type of cross connection is
commonly found in the food
industry and in janitor's sinks. A
hose has been connected to
the faucet on the sink. When
the faucet is left running, a loss
in pressure of the supply main
can siphon this used water
back into the potable water
system.
Submerged Inlets
In many industrial installations
that use chemically treated
baths, the make-up water line
runs directly into the tank. If
there is backsiphonage, the
toxic chemicals can be sucked
back into the potable water
system.
Hose Bibs
At first glance, a hose bib
seems innocuous, but it is the
things people do with the hose
that creates problems. In this
example, a man is trying to
blow a stoppage out in a sewer
line, but with a sudden drop in
line pressure, this contami-
nated water can be
backsiphoned into the potable
water system.
4
Potable
Water Line
Make-up
Water Line
1
Typical .
Cross Connections
Lawn Sprinklers
On a large number of lawn
sprinkler installations the 4)j
sprinkler head is below the
ground level. Water which may
have been in contact with
fertilizers and weed killers can
then be backsiphoned through
a leaky valve into the potable
water system.
Irrigation Pumping Systems
On many farms water is
pumped from irrigation water
channels into the sprinkler
system. A large number of
these installations are also
connected to the domestic
water system for times when
there is little or no irrigation
water available. It is possible
that the pump develops more
pressure than there is in the
domestic supply main and the
irrigation water can then be
pumped through a leaky or
partially open crossover valve.
Fire Sprinkler Systems
On a large number of fire
sprinkler systems there is a
hook up connection for the fire
truck pumper to increase
pressure and flow in the
sprinkler system. At times a
"wetting agent" is added to the
water to increase the effective-
ness of the water in combating
the fire. If the system is not
protected, it is possible for the
pumper to pump this "wet"
water back into the city's
domestic water supply.
5
Backflow Prevention
Devices
There are several different
types of mechanical backflow
prevention device. An alterna-
tive to a mechanical device, is a
physical separation, or air gap.
The air gap is a physical break
in the system. The different
types, of mechanical device,
are used in different situations
(if there is backpressure or
backsiphonage) and for
different degrees of hazard.
The degree of hazard is based
on the fluid (or other substance)
that may backflow into the
supply piping system. The fluid
may be toxic or nontoxic and
could create a "non -health" or
"health" hazard.
A non -health (non-toxic) hazard
cross connection is any point
on a water supply system
where a polluting substance
may come in contact with
potable water aesthetically
affecting the taste, odor or
appearance of the water, but
not hazardous to health.
A health hazard (toxic) cross
connection is any point on a
water supply system where a
contaminating substance may
come in contact with potable
water creating an actual health
hazard, causing sickness or
death.
Double Check
Valve Assembly (DC)
The double check valve
assembly (DC) is composed of
two single, independently
acting check valves. The unit
also has two tightly closing,
resilient seated, shut-off valves
located at each end of the
device and four test cocks for
the testing of the check valves.
6
Reduced Pressure
Principal Assembly (RP)
Commonly referred to as an RP
or RPP, this device consists of
two independently acting check
valves, together with an
automatically operating
pressure differential relief vaive
located between the two check
valves. The first check valve
reduces the supply pressure at
a predetermined amount so
that during normal flow, and at
cessation of normal flow the
pressure between the two
check valves shall be lower
than the supply pressure. If
either check valve leaks, the
relief valve will discharge to
atmosphere. This will maintain
the pressure in the zone
between the two check valves
lower than the supply pressure.
The unit also has two, resilient
seated, shut-off valves (one
upstream and one downstream
of the checks) and properly
located test cocks for field
testing.
Pressure Vacuum
Breaker (PVB)
The pressure vacuum breaker
(PVB) is a device that contains
within a single body, a single
loaded check valve and a
loaded air opening valve which
opens to admit air whenever
the pressure within the body
of the device approaches
atmospheric. The device has
two tight closing, resilient
seated, shut-off valves and it
is fitted with test cocks,
appropriately placed, for testing
the device.
Dual Check Valve (DuC)
The dual check (DuC) is a
device which has two single,
independent acting check
valves in series. It does not
have any testcocks and is
generally not field tested.
Dual Check with
Atmospheric Port (DCAP)
This device has two indepen-
dent acting check valves with a
relief valve located between the
checks. The device is not
testable and should only be
used for lower degrees of hazard.
Atmospheric Vacuum
Breaker (AVB)
An atmospheric vacuum
breaker (AVB) is a device which
has a moving element inside,
which during flow prevents
water from spilling from the
device and during cessation of
flow, drops down to provide a
vent opening. This device
should not remain under
pressure for long durations and
it cannot have any shut-off
valve downstream of it.
Air Gap
An air gap is a physical
separation between the free
flowing discharge end of a
potable pipe line and an open
or non -pressure receiving
vessel. To have an acceptable
air gap, the end of the
discharge pipe has to be at
least twice the diameter of the
pipe above the topmost rim of
the receiving vessel, but in no
case can this distance be less
than one inch.
This may seem to be the
simplest, most effective and
least expensive type of
protection. However, the
chance for future cross -
connections, the cost of
additional pumps to pressurize
the system often makes this an
expensive protection system.
How Backflow
Prevention
Devices Work
This figure shows an RP device
during a backsiphonage
condition. If you will notice both
checks are closed tight and the
pressure differential relief valve
is discharging to atmosphere.
This is due to the fact that the
relief valve is designed to
maintain a lower pressure in
the zone between the two
check valves than the supply
pressure.
In this figure of an RP device,
there is a backpressure
condition. The second check is
fouled with a piece of pipe
scale which permits the higher
pressure to flow back into the
zone. Here the relief valve
discharges the water to
atmosphere maintaining the
pressure in the zone lower than
the supply pressure.
In this view of a pressure
vacuum breaker, a back -
siphonage condition has
caused the check to close
against its seat and the air -inlet
has opened so that the pressure
in the body of the device is
atmospheric. If the check was
fouled by some foreign
material, only air would be
pulled back into the domestic
supply system instead of the
non -potable water downstream
of the device.
In this view of a double check
valve, there is backpressure
from a source downstream
which has caused the second
check to close tightly against
this reverse pressure. The first
check has closed tightly by
itself, thus giving two barriers
against the backflow condition.
In this picture of an
atmospheric vacuum breaker,
a backsiphonage condition
exists. This condition has
caused the check -float to drop
away from the air -inlet and seat
on the check seat, which
prevents the non -potable water
from being backsiphoned. If the
check -float did not seat
properly, again only air would
be sucked back into the
domestic water system.
7
Device Selection Installation
The selection of the proper type
of device is important.
Depending upon the fluid that
can backflow, whether it is toxic
or non-toxic; and whether there
can be backpressure or back -
siphonage; it will govern the
type of device selected. The
following chart will help you to
decide what type of device to use.
Continuous
Pressure
Possible
Back
Pressure
Possible
Back -
siphonage
Nontoxic
Toxic
RP DC
✓ ✓
PVB AVB DuC DCAP
✓ ✓ V
✓ ✓
✓ ✓
✓ ✓
RP - Reduced Pressure Assembly
DC - Double Check Assembly
PVB - Pressure Vacuum Breaker
AVB - Atmospheric Vacuum Breaker
DuC - Dual Check
DCAP - Dual Check with Atmospheric Port
8
Having a device on the
connection is not enough, the
device MUST be installed
correctly. The following details
and illustrations will help you in
the proper installation of the
devices.
Reduced Pressure Device
In these figures, the RP device
is shown on the service
connection. The RP can also be
used for internal protection. The
minimum clearance of 12"
above the floor or grade is to
ensure an air gap between the
relief valve and any water that
might puddle beneath the
device. The maximum height is
so that the device will be easy
to work on during testing and
maintenance. If the device is in
a protective enclosure or
mounted against a wall, the
minimum distances are so that
the device can be tested and
maintained.
Water Meter
Side View
—II�!I:�Qt �II�II
30" Max.
12" Min.
Water Meter .
Top View
Protective
Enclosure
112" Min.
24" Min.
.l
For technical assistance or
product training please call your
local FEBCO representative or
contact the factory direct.
CMB Industries, Inc.
A United Dominion Company
FhN Cuut*I OMdM
FEBCO Backflow Prevention
P.O. Box 8070
Fresno, CA 93747-8070, U.S.A.
Tel 209-252-0791
Fax 209-453-9030
www.cmb-ind.com
CCCHB 11/37
CROSS CONNECTION MODEL ORDINANCE
Purpose and Scope:
Page 1 of 2
(Rev. 9/90)
The purpose of this ordinance is to protect the public health of the water
consumer of the (specify the name of the purveyor) by the control of actual
or potential cross connections.
It shall be the responsibility of the (specify the name of the purveyor)
to protect the public drinking water system from contamination due to
cross connection.
Definitions:
Backflow - The flow other than the intended direction of flow, or any
foreign liquids, gases or substances into the distribution system
of the public drinking water system.
Contamination - The entry into or the presence in the public drinking water
system of any substance or matter when present in drinking
water above an acceptable level may adversely affect the
health of the consumer and/or the aesthetic qualities of
the water consumed.
Cross Connection - Any physical arrangement connecting a public drinking
water system, directly or indirectly, with anything,
other than another public drinking water system, capable
of contaminating the public drinking water system as a
result of backflow.
Department - The Washington State Department of Health.
Public Drinking Water System - Any water system or supply intended or used
for human consumption or other domestic
uses; including source, treatment, storage,
transmission, and distribution facilities
where water is furnished to any community,
collection or number of individuals; however
excluding a system serving one single family
residence.
Purveyor - (Specify the name of the purveyor), or its authorized agent.
Service - A physical connection between the public drinking water system
and the customer's system.
Customer - Any person(s), firm or corporation that is furnished drinking
water through a legal service connection to the drinking water
system.
Illegal User - Any person(s), firm or corporation that is not authorized
by the purveyor to use a customer's service.
Cross Connection:
The installation or maintaining of any actual or potential cross connection
which would endanger the purveyor's public drinking water system is
prohibited. Any such cross connection now existing is hereby declared
unlawful and shall be removed immediately or face penalty.
Water service to any premise shall be contingent upon the customer providing
cross connection control in a manner approved by the purveyor.
The control or elimination of cross connection shall be in accordance with
the State of Washington Administrative Code (WAC 248-54-285), or any
superseding edition.
The policies, procedures and criteria for determining appropriate levels
of protection shall be in accordance with the Accepted Procedure and
Practice in Cross Connection Control Manual - Pacific Northwest Section -
American Waterworks Association, Fifth Edition, or any superseding edition,
however, the legal governing body (as Board of Directors) of the purveyor
may establish requirements for cross connection control more stringent than
the state regulation if it is determined that conditions so dictate.
Backflow Assemblies:
Backflow assemblies required to be installed shall be a model approved by
the department and shall be tested a minimum of once a year.
Penalty:
Service to any premise receiving its water from the purveyor's public
drinking nater system shall be contingent upon compliance with all rules
and regulations of the department and the purveyor. Service shall be
discontinued to any premise for failure to comply with the rules and
regulations of the department and this purveyor.
(Rev. 1/91)
* BACKFLOW ASSEMBLY APPROVAL *
AWWA STANDARDS SETS THE DESIGN, MATERIAL AND OPERATIONAL SPECIFICATIONS
USC (FCCCHR) PERFORMS THE LABORATORY AND FIELD TESTING. WILL EITHER APPROVE OR
DISAPPROVE THE ASSEMBLY IN ACCORDANCE WITH THE AWWA STANDARD
THE STATE DEPARTMENT OF HEALTH HAS THE FINAL DECISION AS TO WHICH ASSEMBLY WILL
BE APPROVED FOR INSTALLATION IN ITS OWN STATE
AWWA STANDARD C510-89 DOABLE CHECK VALVE BACKFLOW PREVENTION ASSEMBLY AND C511-89
REDUCED PRESSURE PRINCIPLE BACKFLOW PREVENTION ASSEMBLY, PVBA STANDARDS ARE
INTERPOLATED AND EXTRAPOLATED, BY USC (FCCCHR), FROM AWWA STANDARD C510-89.
EXAMPLES OF THE SPECIFICATIONS:
1. DISASSEMBLE AND REPAIR IN LINE FOR ALL SIZES
2. RATED FLOW MUST BE EQUAL TO THE RATED FLOW OF A DISPLACEMENT OR COMPOUND
METER OF THE CORRESPONDING SIZE
3. AT THE RATED FLOW, THE ASSEMBLIES ARE ALLOWED A MAXIMUM AMOUNT OF HEAD LOSS
EXAMPLE: 2" ASSEMBLY, RATED FLOW 160 GPM, HEAD LOSS - RP 16 PSI, DCVA
AND PVBA 10 PSI
4. WITHSTAND HYDROSTATIC WATER PRESSURE OF 300 PSI AND MAXIMUM WORKING
WATER PRESSURE OF 150 PSI
5. SOFT SEATED DISC MATERIAL IS MADE OF A MOLDED SYNTHETIC RUBBER WITH A
SHORE HARDNESS BETWEEN 35 AND 45
6. CHECK VALVES MUST BE INTERNALLY LOADED AND MUST BE DRIP -TIGHT IN THE
DIRECTION OF FLOW WITH A MINIMUM OF 1 PSI DIFFERENTIAL
7. MUST BE EQUIPPED WITH 2 FULLY PORTED, RESILIENT SEATED, SHUT OFF VALVES
AND 4 FULLY PORTED, RESILIENT SEATED, TEST COCKS
8. CERTAIN MARKINGS ARE REQUIRED SUCH AS: NAME OR TRADEMARK, SIZE, TYPE,
SERIAL *, MODEL :, DIRECTION OF FLOW, MAXIMUM WORKING WATER PRESSURE AND
TEMPERATURE
* BACKFLOW ASSEMBLY APPROVAL *
EVALUATION OF DESIGN AND PERFORMANCE
Page 2 of 2
(Rev. 1/91)
1. APPROVED TESTING LABORATORY
A. FOUNDATION FOR CROSS CONNECTION CONTROL AND HYDRAULIC RESEARCH,
UNIVERSITY OF SOUTHERN CALIFORNIA, USC (FCCCHR)
B. IN ACCORDANCE WITH AWWA STANDARDS C510-89 AND C511-89
2. DRAWINGS AND MATERIAL SPECIFICATIONS ARE SUBMITTED FOR EACH SIZE AND MODEL
OF ASSEMBLY
3. LABORATORY EVALUATION
A. ASSEMBLIES ARE SELECTED AT RANDOM
B. DESIGN AND OPERATIONAL SPECIFICATIONS ARE EVALUATED
4. FIELD TESTING
A. THREE ASSEMBLIES OF THE SAME SIZE AND MODEL ARE INSTALLED IN THE "FIELD"
B. THE THREE ASSEMBLIES ARE REQUIRED TO PASS MONTHLY PERFORMANCE TESTS FOR
12 CONSECUTIVE MONTHS
5. APPROVAL
A. ASSEMBLIES ARE EITHER APPROVED OR DISAPPROVED
B. THE TESTING LABORATORY WILL ISSUE A LIST WITH ALL THE ASSEMBLIES THAT IT
APPROVES
C. APPROVAL OF THE ASSEMBLIES IS VALID FOR A MAXIMUM OF 3 YEARS AT WHICH
TIME THEY ARE RE-EVALUATED
Potential Cross Connection Areas
If potable Nater is connected to the following fixtures or facilities, ootential or
actual cross connections may exist.
Air Compressors
Air Conditioned Chillwater
Air Conditioning Systems
Air Conditioning Condenser Water
Air Washers
Aspirators, Medical
Aspirators, Weedicide & Pesticide
Autoclaves
Autopsy Tables
Auxiliary Water Supplies *
Baptismal Fount
Bathtub Below Rim Filler
Bedpan Washer, Flushing Rim
Beverage Dispensers
Beverage Processing Plants *
Bidet
Boat Marina *
Boat Repair Facilities
Boiler Feed Line
Bottle Washer
Box Hydrants
Brine Tanks
Car Washes *
Chemical Feeder
Chemical Plants
Chiller Tanks
Chlorinator
Clinics *
Coffee Urns
Computer Cooling Lines
Condensate Tanks
Cooking Kettles
Cooling Towers
Chiller Tanks
Dairy Equipment
Degreasing Equipment
Demineralized System
Dental Cuspidors
Detergent Dispenser
Digesters, Hospital
Dishwasher
Drinking Fountain
Dry Cleaners
Dye Vats & Tanks
Dye Vats and Tanks
Dynometer
Etching Tanks
Fermenting Tanks
Fertilizer Injection Systems
Film Processors
Fire Department Connections
Fire Sprinkler Systems
Tanks
*
-1-
Food Processing Plants
Floor Drains, Flushing
Foamite Systems
Fountain, Ornamental
Garbage Can Washer
Garbage Disposers
Graving Docks
Heat Exchangers
High Pressure Washers
Hose Gibbs
Hose, Kitchen Rinse
Hospitals *
Hot Tubs
Hot Water Heater & Tanks
Humidifier Tank & Boxes
Hydrotherapy Baths
Ice Makers
Irrigation Sysems
Janitor Sinks
Kitchen Equipment
Laboratories *
Laboratory Equipment
Laundry Machines
Lavatories
Lawn Sprinkler Systems
Livestock Drinking Tanks
Make Up Tanks
Marinas *
Metal Plating Plans *
Mobile Carpet Cleaners
Mortuaries *
Nuclear Reactors *
Outboard Motor Test Tanks
Petroleum Processing Plants *
Petroleum Storage Facilities *
Photo Developing Tanks
Photo Lab Sinks
Photostat Equipment
Piers and Docks *
Pipette Washers
Plating Plants *
Potato Peelers
Private Hydrants
Processing Tanks
Pump Seal Water
Pump, Pneumatic Ejector
Pump Prime Lines
Pump, Water Operated Ejector
Pump, Prime Line
Pump, Water Operated Ejector
Radiator Flushing Equipment
Radioactive Material Processing
*
*
'Cross-4onnectiod Control
http://www.mindspring.conil—loben/dep-panthtm
QUESTIONS AND ANSWERS ABOUT
CROSS -CONNECTION CONTROL
Florida Department of Environmental Protection
QUESTION: What is a cross -connection?
ANSWER: A cross -connection is any temporary or permanent connection between a public water
system or consumer's potable (i.e., drinking) water system and any source or system containing
nonpotable water or other substances. An example is the piping between a public water system or
consumer's potable water system and an auxiliary water system, cooling system, or irrigation system
QUESTION: What is backflow?
ANSWER: Backflow is the undesirable reversal of flow of nonpotable water or other substances through
a cross -connection and into the piping of a public water system or consumer's potable water system.
There are two types of backflow... backpressure backflow and backsiphonage.
QUESTION: What is backpressure backflow?
ANSWER: Backpressure backflow is backflow caused by a downstream pressure that is greater than the
upstream or supply pressure in a public water system or consumer's potable water system. Backpressure
(i.e., downstream pressure that is greater than the potable water supply pressure) can result from an
increase in downstream pressure, a reduction in the potable water supply pressure, or a combination of
both. Increases in downstream pressure can be created by pumps, temperature increases in boilers, etc.
Reductions in potable water supply pressure occur whenever the amount of water being used exceeds the
amount of water being supplied, such as during water line flushing, fire fighting, or breaks in water mains.
QUESTION: What is backsiphonage?
ANSWER: Backsiphonage is backflow caused by a negative pressure (i.e., a vacuum — or partial
vacuum) in a Public water system or consumer's potable water system. The effect is similar to drinking
water through a straw. Backsiphonage can occur when there is a stoppage of water supply due to nearby
fire fighting, a break in a water main, etc.
QUESTION: Why do water suppliers need to control cross -connections and protect their public water
systems against backflow?
ANSWER: Backflow into a public water system can pollute or contaminate the water in that system (i.e.,
backflow into a public water system can make the water in that system unusable or unsafe to drink), and
each water supplier has a responsibility to provide water that is usable and safe to drink under all
foreseeable circumstances. Furthermore, consumers generally have absolute faith that water delivered to
them through a public water system is always safe to drink. For these reasons, each water supplier must
take reasonable precautions to protect its public water system against backflow.
QUESTION: What should water suppliers do to control cross -connections and protect their public
1 of 4 12/17/97 4:41 PM
Cross -Connection Control
2 of 4
http://www.mindspring.corn/--loben/dep-pam.htm
water systems against backflow?
ANSWER: Water suppliers usually do not have the authority or capability to repeatedly inspect every
consumer's premises for cross -connections and backflow protection. Alteratively, each water supplier
should ensure that a proper backflow preventer is installed and maintained at the water service connection
to each system or premises that poses a significant hazard to the public water system. Generally, this
would include the water service connection to each dedicated fire protection system or irrigation piping
system and the water service connection to each of the following types of premises: (I) premises with an
auxiliary or reclaimed water system: (2) industrial, medical, laboratory, marine or other facilities where
objectionable substances are handled in a way that could cause pollution or contamination of the public
water system; (3) premises exempt from the State Plumbing Code and premises where an internal
backflow preventer required under the State Plumbing Code is not properly installed or maintained; (4)
classified or restricted facilities; and (S) tall buildings. Each water supplier should also ensure that a
proper backflow preventer is installed and maintained at each water loading station owned or operated by
the water supplier.
QUESTION: What is a backflow preventer?
ANSWER: A backflow preventer is a means or mechanism to prevent backflow. The basic means of
preventing backflow is an air gap, which either eliminates a cross -connection or provides a barrier to
backflow. The basic mechanism for preventing backflow is a mechanical backflow preventer, which
provides a physical barrier to backflow. The principal types of mechanical backflow preventer are the
reduced -pressure principle assembly, the pressure vacuum breaker assembly, and the double check valve
assembly. A secondary type of mechanical backflow preventer is the residential dual check valve.
QUESTION: What is an air gap?
ANSWER: An air gap is a vertical, physical separation between the end of a
water supply outlet and the flood -level rim of a receiving vessel. This
separation must be at least twice the diameter of the water supply outlet and
never less than one inch. An air gap is considered the maximum protection
available against backpressure backflow or backsiphonage but is not always
practical and can easily be bypassed.
QUESTION: What is a reduced principle assembly (RP)?
ANSWER: An RP is a mechanical backflow preventer that consists of two
independently acting, spring-loaded check valves with a hydraulically
operating, mechanically independent, spring-loaded pressure differential
relief valve between the check valves and below the first check valve. It
includes shutoff valves at each end of the assembly and is equipped with
test cocks. An RP is effective against backpressure backflow and
backsiphonage and may be used to isolate health or nonhealth hazards.
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12/17/97 4:41 PM
'Cross -Connection Control
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QUESTION: What is a pressure vacuum breaker assembly (PVB)?
ANSWER: A PVB is a mechanical backflow preventer that consists of an
independently acting, spring-loaded check valve and an independently acting,
spring-loaded, air inlet valve on the discharge side of the check valve. It
includes shutoff valves at each end of the assembly and is eqipped with test
cocks. A PVB may be used to isolate health or nonhealth hazards but is
effective against backsiphonage only.
QUESTION: What is a double check valve assembly (DC)?
http://www.mindspring.conil—loben/dep-pam.htm
ANSWER: A DC is a mechanical backflow preventer that consists of two
independently acting, spring-loaded check valves. It includes shutoff valves at
each end of the assembly and is equipped with test cocks. A DC is effective
against backpressure backflow and backsiphonage but should be used to
isolate only nonhealth hazards.
QUESTION: What is a residential dual check valve (rdc)?
ANSWER: A rdc is similar to a DC in that it is a mechanical backflow preventer consisting of two
independently acting, spring-loaded check valves. However, it usually does not include shutoff valves,
mar or may not be equipped with test cocks or ports, and is generally less reliable than a DC. A rdc is
effective against backpressure backflow and backsiphonage but should be used to isolate only nonhealth
hazards and is intended for use only in water service connections to single-family homes.
QUESTION: Why do backflow preventers have to be tested periodically?
ANSWER: Mechanical backflow preventers have internal seals, springs, and moving parts that are
subject to fouling, wear, or fatigue. Also, mechanical backflow preventers and air gaps can be bypassed.
Therefore, all backflow preventers have to be tested periodically to ensure that they are functioning
properly. A visual check of air gaps is sufficient, but mechanical backflow preventers have to be tested
with properly calibrated gauge equipment.
QUESTION: Where can I get more information about cross -connection control?
ANSWER: One excellent reference manual is the second (1990) edition of the American Water Works
Association's (AWWA's) Manual M14, Recommended Practice for Backflow Prevention and
Cross -Connection Control, which is available from the AWWA Bookstore; 6666 West Quincy Avenue;
Denver, Colorado 80235; 800/926-7337; httn://www.awwa.org. Another excellent reference manual is
the ninth (1993) edition of the University of Southern California's Manual of Cross -Connection Control,
which is available from the Foundation for Cross- Connection Control and Hydraulic Research;
University of Southern California; KAP -200 University Park MC -2531; Los Angeles, California
90089-2531; 213/740-2032;
http://www.usc.edu/dept/fccchr.
State of Florida
Dept. Of Environmental Protection
Division of Water Facilities
Bureau of Water Facilities Regulation
12/17/97 4:41 PM
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STATE OF IDAHO
DEPARTMENT OF
ENVIRONMENTAL QUALITY
RECEIVED :;1 2 2003
1445 North Orchard • Boise, Idaho 83706-2239 • (208) 373-0550 Dirk Kempthorne, Governor
C. Stephen Allred, Director
February 14, 2003
Mr. Robert Strope
City Manager
P.O. Box 986
McCall, ID 83638
RE: City of McCall Water Treatment Plant
SRF DW Loan 9906 - Loan Closeout
Dear Mr. Strope:
The Loan Offer, Acceptance, and Contract (Contract) explains City requirements. Some of the conditions
are self -certifying or ongoing. Listed below are the remaining items that DEQ must review and approve
prior to loan closeout.
1. Final approval of all Change Orders. I am working with Brad Bjerke of Donohue & Associates on
those.
2. Final Pay Request.
3. User Charge. System and Water System Protection Ordinance. These two documents are listed in
two places in the Contract and I believe there was some confusion about that when the City
provided the schedule in the Contract. "Enacted" refers to the approved City ordinance, which I
presume was what you meant when you listed them as completed. "Approved" refers to DEQ
approval. Please complete as much of the attached checklist as possible and forward the checklist
and those two documents for review and approval. I will review the documents and sign the
checklist, then issue the approval when appropriate.
4. Operation and Maintenance Manual. Ginny Carol of Donohue & Associates will be submitting
that document and the associated checklist in the next week or so.
5. Certification of filtration performance according the DEQ guidance. Ginny Carol of Donohue &
Associateswill be submitting that information for review and approval in the next week or so.
Please call me with any questions at 373-0560 or via e-mail at mmarchus@deq.state.id.us.
Sincerely,
C-. 9M4A414-
Monty G. Manchus, P.E.
Staff Engineer
MGM:ve: H:\MCCALL\SRF Loan\Loan Close-out-1.doc
Enclosure: Drinking Water Loan Account Checklist For User Charge System (UCS)
And Water System Protection Ordinance Review
cc: Bill Jerrel, DEQ -State Office
Jack Gantz, DEQ -Boise Regional Office
Brad Bjerke, P.E., Donohue & Associates
Reading file, Source file #13.5, Manager's file