22-1718ORDINANCE NO. 22-1718
AN ORDINANCE OF THE CITY OF DENTON, TEXAS AMENDING THE WATER ANDWASTEWATER CRITERIA MANUAL; AND PROVIDING FOR SEVERABILITY, ASAVINGS CLAUSE AND AN EFFECTIVE DATE.
WHEREAS, pursuant to Ordinance No. DCA 18-0009q, the City Council of the City of
Denton, a Texas home-rule municipal corporation (the “City”) adopted the newly revised Denton
Development Code, superseding and expressly repealing Chapters 31, 34 and 35 of the 1991Code of the City of Denton, Texas, as amended, and leaving all other Chapters intact and
superseding and expressly repealing the 2002 Denton Development Code, as amended; and
WHEREAS, the Denton Development Code established a process whereby the policies,
regulations, and procedures relating to zoning and development within the City and its regulatory
extraterritorial jurisdiction are legislatively established by the Council after public hearing in
acccordance with State law; and
WHEREAS, the creation of specific design standards and methodologies (the
“Development Criteria Manual”) are delegated to staff of professionals possessing the necessary
and appropriate licensure and expertise who may also consult with their peers in both the public
and private sectors, consistent with the policy direction of Council; and
WHEREAS, the Development Criteria Manual process was intended to benefit the public
and the development community by empowering City professional staff to more quickly
implement new and improved materials and methods as they are developed, in accordance withgenerally accepted design standards of the industry, as appropriate to achieving an equal or
greater public benefit for costs expended, for issues not involving policymaking decisions; and
WHEREAS, the latest version of the Water and Wastewater Criteria Manual was last
prepared in December 2021; and
WHEREAS, the Water and Wastewater Criteria Manual update will be adopted by
ordinance; and
WHEREAS, after providing notice and conducting a public hearing as required by State
law, the City Council finds that these changes to the Water and Wastewater Criteria Manual areconsistent with the Comprehensive Plan and are in the public interest; NOW THEREFORE,
THE COUNCIL OF THE CITY OF DENTON HEREBY ORDAINS:
SECTION 1. The findings and recitations contained in the preamble of this ordinance
are incorporated herein by reference.
SECTION 2. The Water and Wastewater Criteria Manual is hereby amended and shall
read as contained in Exhibit “A.”
SECTION 3. It is hereby officially found and determined that the meeting at which this
Ordinance was passed was open to the public as required by law, and that public notice of the
time, place, and purpose of the meeting was given as required by State law.
SECTION 4. If any section, subsection, paragraph, sentence, clause, phrase, or word in
this Ordinance, or the application thereof to any person or under any circumstances is held invalid
by any court of competent jurisdiction, such holding shall not affect the validity of the remaining
portions of this Ordinance, and the City Council of the City of Denton, Texas hereby declares it
would have enacted such renaming provisions despite any such invalidity.
SECTION 5. Save and except as amended hereby, all the provisions, sections,
subsections, paragraphs, sentences, clauses, and phrases of the code of Ordinances shall remain
in full force and effect.
SECTION 6. This ordinance shall become effective January 1, 2023 .
The motio{1 JO apprqve thip ordinance was made by edan eRa and seconded
by vtIn eRA\ d , the ordinance was passed and approved by the
following vote Q - 1}]:
Aye
1/
\/
/
\/
Nay Abstain Absent
Gerard Hudspeth, Mayor:
Vicki Byrd, District 1 :
Brian Beck, District 2:
Jesse Davis. District 3:
VACANT, District 4:
Brandon Chase McGee, At Large Place 5: r
Chris Watts, At Large Place 6: /
PASSED AND APPROVED this, the a day of OecLh& @( 2022.
GERARD HUDSPETH, MAYOR
ATtEST:
ROSA RIOS, CITY SECRETARY b\\\lULl /////
+=n }?,a .a4
APPROVED AS TO LEGAL FORM:
MACK REINWAND, CITY ATTORNEY
BY: B+waS(hd'- ff 9f€i3£===-'-'u-
City of DentonExhibit A
Water and Wastewater Criteria Manual
DENTON
October 2022
Table of Contents
Water and Wastewater Criteria Manual
TABLE OF CONTENTS
SECTION 1 - INTRODUCTION....................................................................................................................4
1.1 PURPOSE ..................................................................................................................................4
SECTION 2 - REMOVED.............................................................................................................................. 5
SECTION 3 - WATER DESIGN GUIDELINES ............................................................................................ 6
3.1
3.2
3.3
3.3.13.3.2
3.3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
3.11
3.12
3.13
3.14
3.15
3.16
3.16.1
3.16.23.16.3
3.16.4
3.17
3.18
3.19
3.20
3.20.13.20.2
3.20.3
3.21
GENERAL ..................................................................................................................................6
WATER MAIN SEPARATION FROM WASTEWATER MAINS...............................................................6
SIZE OF WATER DISTRIBUTION MAINS.........................................................................................6
Public Fire Hydrants ........................_........................_.........._.........__........................._............_.................. 8Private Fire Mains ........................................................................................................................................... 8Fire Flow Tests................................................................................................................................................ 8
DEPTH OF COVER FOR WATER MAINS ........................................................................................ 9
PIPEANDFIrrINGS ....................................................................................................................9
METERS AND METER CANS/VAULTS ......................................................................................... 11
WATER MAIN HORIZONTAL AND VERTICAL ALIGNMENT .............................................................. 20
HIGHWAY CROSSINGS..............................................................................................................21
RAILROAD CROSSINGS.............................................................................................................21
CREEK CROSSINGS ...............................................................................................................-.21
TUNNELING, BORING, JACKING AND CASING.............................................................................. 22
ELEVATED CROSSINGS ............................................................................................................ 22
UNDERGROUND UTILItY CROSSINGS ........................................................................................ 22
FENCE OR WALL CROSSINGS .................................................................................................. . 24
EXISTING WATER MAIN REPLACEMENT ..................................................................................... 24
METHODS OF CONNECTION ......................................................................................................25
Pressure Zones ............................................................................................................................................. 25
Tapping Sleeve and Valve............................................................................................................................. 27Cut-In Connection ..._._....__............._..................................._........__......._..__......_.............._.................. 27Main Extensions ............................................................................................................................................ 27
VALVES .................................................................................................................................-. 27
DEAD-END MAINS .................................................................................................................... 29
FIRE HYDRANT LOCATIONS AND COVERAGE.............................................................................. 29
REQUIREMENTS FOR ABANDONING WATER MAINS..................................................................... 29
Replacement Mains....................................................................................................................................... 30Extension Mains ............................................................................................................................................ 30
Fire Hydrants................................................................................................................................................. 30
FLUSHING AND DISINFECTION ................................................................................................... 30
SECTION 4 - WASTEWATER DESIGN GUIDELINES ............................................................................. 32
4.1
4.2
4.4
4.4.1
4.5
GENERAL ................................................................................................................................ 32
ESTIMATED WASTEWATER FLOWS ............................................................................................ 32
SIZE AND SLOPE OF SEWERS ................................................................................................... 34
High Velocity Protection ............_.._..........................................._....._...._.._............_........_........................ 35
SEWER MAIN DEPTH ......................,......................................................................................... 35
2
Table of Contents
Water and Wastewater Criteria Manual
4.6
4.7
4.8
4.9
4.10
4.11
4.11.1
4.12
4.13
4.14
4.15
4.16
4.17
4.18
4.19
4.20
4.21
4.21 .14.21.24.21.34.21.4
4.21.54.21.6
4.22
4.23
4.24
5.1
5.2
5.3
5.4
RECOMMENDED COVER ...........................................................................................................35
SEWER ALIGNMENT ......................................................................................,..........................35
SEWERLATERALS.................................................................................................................... 36
GRAvtrr’ AND FORCE MAIN SEWER PIPE MATERIAL................................................................... 36
SEWERPIPEEMBEDMENT ........................................................................................................ 37
MANHOLES.............................................................................................................................. 37
Manhole Locations ........................................................................................................................................ 38
HIGHWAY CROSSINGS.............................................................................................................. 38
RAILROAD CROSSINGS............................................................................................................. 38
TUNNELING, BORING, JACKING AND CASING..................................................,........,.................. 38
UNDERGROUNDUTILIIV CROSSINGS ............................................................,........................... 39
FENCE OR WALL CROSSINGS ..................,................................................................,............... 39
CREEK CROSSINGS .................................................................................................................39
SIPhlONS .................................................................................................................................39
ABANDONMENT OF SEWER MAINS ............................................................................................ 39
ABANDONMENT OF MANHOLES .............................................,...................................................40
LIrr STATIONS......................................................................................................................... 40
Preliminary Design Submittal......................................................................................................................... 40Site Layout .................................................................................................................................................... 41Hydraulic Design ........................................................................................................................................... 44PLlrnps........................................................................................................................................................... 45Mechanical .................................................................................................................................................... 45
Electrical, Instrumentation and Supervisory Control and Data Acquisition (SCADA) Requirements ............... 48
LOW PRESSURE COLLECTION SYSTEMS ......................................................,............................48
ON-SITE SEWAGE FACILITIES ..............................................,....................................................48
GREASE TRAP / GRIT TRAPS ....................................................................................................48
(3ENERAL ................................................................................................................................51
RESPONSIBILIIY ......................................................................................................................51
FORMAT . ............,,,,...................................................................................,,,...........................51
PLAN REQUIREMENTS ..............................................................................................................51
Section 1
Water and Waste*fvater Criteria Manual
Section 1 – Introduction
1.1 Purpose
The purpose of this Manual is to provide minimum, non-exhaustive guidelines for thedesign and construction of water distribution and wastewater collection systems withinthe City of Denton, Texas and its extra-territorial jurisdictions. The criteria established inthis Manual have been developed from a review of various applicable publications,
regulatory requirements, and City of Denton offices which oversee the design,construction and maintenance of the water distribution and wastewater collection
systems
These guidelines are to be used by design engineers in the City of Denton CapitalProjects Engineering Division, consulting engineers employed by the City, and engineersof subdivision and land development infrastructure projects proposed for constructionand acceptance by the City within its Certificate of Convenience and Necessity (CCN)area. The criteria established in this Design Manual provide basic guidance. However,full responsibility and liability for proper design remains with the design engineer.Users of this Manual should be knowledgeable and experienced in the theory andapplication of water and wastewater engineering. Variances sought for deviations
from criteria in this Manual will require additional time to evaluate, and receive approvalfrom the City Engineer, in consultation with the Director of Water Utilities.
Along with this Manual, the Denton Development Code (DDC)should be consulted foradditional criteria. The criteria established in this Manual do not supersede the criteriacontained in the DDC. In the case of conflict among this Manual, , City of DentonStandard Details, or other cited regulations and standards, the more stringentrequirement shall apply.
Section 1
PVafer and
5
yyd5£eyv aCe/– vfILeFia IVI afi ua/nI
Section 2 - Removed
Section 3
Water and Wastewater Criteria Manual
Section 3 – Water Design Guidelines
3. f General
It is the responsibility of the design engineer to ensure the final design of a water main isin conformance with the most recent versions of the following documents:
A.
BC
DE
FG.
Texas Administrative Code (TAC) Title 30, Part 1, Texas Commission on
Environmental Quality (TCEQ) – Rules, Ch. 290, “Public Drinking Water”Public Utilities Commission (PUC) Chapter 24City of Denton Code of Ordinances and Denton Development Code (DDC)This Manual
The City of Denton’s Standard Details and Standard Specifications for ConstructionCity of Denton Water Utilities Master PlansThe 2021 International Fire Code American Water Works Association (AWWA)Standards
3.2 Water Main Separation from Wastewater Mains
Water mains shall be separated from wastewater mains as set forth in Texas
Administrative Code (TAC) Title 30, Part 1 , Texas Commission on Environmental Quality(TCEQ) Rules - 30 TAC $290.44.e. Location of waterlines or as mostly recentlyamended
3.3 Size of Water Distribution Mains
Water mains shall be sized to meet the calculated water demand, fire flow protection
requirements, and to conform to the City of Denton’s Water Distribution System MasterPlan (Master Water Plan). All residential, commercial, industrial, and any other
development connecting to the City’s water distribution system shall use the followingguidelines:
A.The design engineer shall obtain the record drawing water maps from the Capital
Projects Engineering Division and use the following criteria, based on the City’sMaster Water Plan, for sizing the water lines.
• Average daily demand in gallons per capita per day = 170 GPCDMaximum daily demand / Average daily demand = 2.0Peak hour demand / Maximum daily demand = 1.5
• For Single-Family Residential – Use 3.2 people/unit
• For Multi-Family Residential – Use 2.5 people/unit
B Water systems shall be provided with a sufficient number of connections to the City’s
existing water system and shall be of sufficient size to furnish adequate water supplyto furnish fire protection to all lots and conform to the City Master Water Plan. Everynew water system shall include two or more connections to the existing City watersystem, when feasible, to ensure an adequate and reliable water supply in the eventof a water main break or routine system maintenance. The City may require two ormore meter connections, particularly for larger developments. Good engineering
6
Section 3
Water and Wastewater Criteria Manuai
judgement is required to ensure reliability is considered in design of all proposedwater systems.
C. The City’s standardized water service line sizes are:
Table 3.3-1
Service Size Meter Sizem2 in4 in6 in8 in
M:mEmA1REMEn1-1/2 in. and 2 in.3 in. and 4 in6 in8 in
Non-standard sized water services are not allowed. Refer to the water service
connection drawings on the City Standard Details.
D. Sites that require an irrigation meter shall have two separate service line connectionsonto the main; one for the domestic meter, the other for the irrigation meter.
E Water pipe shall be a minimum of 8 inches in diameter. The standard pipe sizes thatshall be used for water main lines are 8”, 12”, 16”, 20”, 24”, 30”, 36” and 42”. Pipesizes of 6”, 10”, 14”, 18”, 21 ”, and 33” are considered non-standard by the City and
shall not be used for water main lines. Six (6) in. pipe may be used for fire hydrantconnections.
F Every development shall provide adequate water capacity for fire protectionpurposes. Fire flow capacity requirements are in addition to daily demand
requirements. The procedure for determining fire flow requirements for buildings orportions of buildings shall be in accordance with version of the International FireCode adopted in the City. For any platted lot where the end use is not defined, thestandards in Table 3.3-2 shall apply.
Table 3.3-2
GPM
1 ,000
1 ,500
3,000
4,000
One and two EHa!!HEHnBHgIlathan 3,600 SF
Buildings other than one and twodwellings less than 3,600 SF
c
ht industrial
l
industrial
All fire flows to be calculated with twenty (20) pounds residual
pressures.
In addition to the fire flow requirements specified above, all
developments shall provide adequate water capacity to satisfy
7
Section 3
Water and Wastewater Criteria Manual
the greater of (1) Peak Hour demand for the Peak Day or (2)Average Hour demand plus fire flow for the Peak Day.
Mains are to be sized to ensure less than 1 foot of head loss
per 1,000 feet of water main at Hazen Williams coefficients ofC = 100, except for fire flow demands within the subdivision
internal distribution system.
Special exceptions to the above standards may be made bythe Director of Water Utilities for unique situations.
3.3.1 Public Fire Hydrants
Fire flow requirements shall be in accordance with Ch. 29 of the City of Denton Code ofOrdinances and Appendix B of the 2021 International Fire Code.
3.3.2 Private Fire Mains
In addition to the requirements of 3.3.1, private fire protection water mains shall be
installed in accordance with NFPA 24 and 2021 International Fire Code requirements.Private fire protection mains shall be permitted by the Fire Marshall’s Office.
3.3.3 Fire Flow Tests
Fire flow tests are normally requested by the design engineer, the Mechanical, Electricaland Plumbing (MEP) engineer, and other engineers to determine available water systemcapacity at or near the point of interest. If a fire flow test on the existing water system is
necessary, contact the Water Metering Department at (940) 349-8456 directly.
Section 3
Water and Wastewater Criteria MarIua:
3-4 Depth of Cover for Water Mains
The following guidelines shall govern depth of cover for water main installations:
Table 3.4-1
Water Main under unpaved areas
Pipe Size
12" and smaller
16" and larger
Minimum Depth of cover fromsurface to top of pipe
5'
6
Table 3.4-2
Water Main under proposed or existing pavement
Pipe Size
12” and smaller
16”
20” and larger
Minimum Depth of cover fromsurface to top of pipe
42”
5
6’
Additional depth of cover shall be required for low lying areas where future drainage
improvements are anticipated.
3-5 Pipe and Fittings
Specifying the appropriate pipe material is the responsibility of the design engineer,based on the analysis of specific site and loading conditions and pressure requirements.The minimum requirements in this Section are based on pipe size only and in no way
relieve the design engineer of the responsibility of specifying the pipe material applicableto the specific project. Pipe gasket material shall be that recommended by themanufacturer for the specified pipe. Special attention shall be given by the design
engineer for unique pipe fitting and pipe assembly situations.
See Table 3.5-1 for the City’s minimum pipe materials, fittings, polywrap, thrust restraint,and embedment requirements, as a function of pipe size.
All fittings for pipe sizes less than 30 inches in diameter, including vertical and horizontalbends, shall have concrete thrust blocking. See City of Denton Standard Details .
For all water line sizes, all fittings, including vertical and horizontal bends, shall haverestrained joints, designed independently of concrete thrust blocking. For water linesgreater than 12 inches in diameter additional restrained joints may need to be installedbeyond the fitting (i.e., may need to be installed on several pipe joints on each side of
the fitting), depending on the required restrained length calculated. Restrained length
9
Section 3
Water and Wastewater Criteria Manual
calculations shall be included in the lay schedule in the material submittal package andshall use approved methods of joint restraint. See City Standard Details, specific product
listings and Table 3.5-1 .
Table 3.5-1
Minimum Requirements for Pipe and Fittings
D
Fittings
lrctlle Iron Polywrap(Pipe &Fittings)
Thrust Restraint
Pipe Size Pipe Material D 0
(IN ADDITION TO ANDESIGNED INDEPENDENTLYF THRUST BLOCKING
Embeclment
8 in. - 12 in.PVC
(AWWA C900, DR-14)
joint;Compact orFull-Bod.
[:mM;HeEnhanced
Polywrap(fitting onI:
Wedge-action mechanical jointrestraint glands, at fittings.
See drawings U201,U202, U203A. U203C
in City Standard Details
Ductile Iron. AWWA
C151, SpecialThickness Class
52, push-on joints
(whereunrestrained;
example:American Flex-Ring
oint=
8-mil V-BioEnhanced
Polywrap(inner layer),plus 4-milcross-linked
(outer layer)
Wedge-action mechanical jointrestraint glands, at fittings.Boltless Restrained connections
(Example: American Flex-Ringjoint), at several pipe joints eitherside of each fitting, depending onthe required restrained lengthcalculated.
Mechanical
joint;Full-Body
See drawings U201,U202, U203A, U203C
in City Standard Details
16 in. - 20 in.
ReinforcedConcrete Steel
Cylinder, AWWAC303 Bar Wrapped
Bonded jointand CathodicProtection
(CP) Systemrequired
N/A Full Circle Welded Joints requiredfor thrust restraint Contact Water Utilities
Dept.
Ductile Iron, AWWAC151, SpecialThickness Class
52, push-on joints
(whereunrestrained ;
example:
American Flex-Ringaint]
8-mil V-BioEnhanced
Polywrap(inner layer),plus 4-milcross-linked
(outer layer)
Wedge-action mechanical jointrestraint glands, at fittings.Boltless Restrained connections
(Example: American Flex-Ring
joint), at several pipe joints eitherside of each fitting, depending onthe required restrained lengthcalculated.
Mechanical
joint;
Full-Body
Crushed Stone
24 in.
Reinforced
Concrete Steel
Cylinder, AWWAC303 Bar Wrapped
Bonded jointand Cathodic
Protection(CP) System
required
N/A Full Circle Welded Joints requiredfor thrust restraint.Contact Water Utilities
Dept.
Ductile Iron,Pressure Class
350; push-on joints
(whereunrestrained;
example:American Flex-Ring
joint:
8-mil V-BioEnhanced
Polywrap
(inner layer),plus 4-milcross-linked
(outer layer)
Wedge-action mechanical joint
restraint glands, at fittings.Boltless Restrained connections
(Example: American Flex-Ringjoint), at several pipe joints eitherside of each fitting, depending onthe required restrained lengthcalculated.
Mechanical
joint;
Full-Body
Crushed Stone
30 in. andlarger
ReinforcedConcrete Steel
Cylinder, AWWAC303 Bar Wrapped
Bonded jointand CathodicProtection
(CP) Systemrequired
N/A Full Circle Welded Joints requiredfor thrust restraint.Contact Water Utilities
Dept.
10
Section 3
Water and Wastewater Criteria Manual
3.6 Meters and Meter Cans/Vaults
The City allows the following water meters, depending on the volume and nature of thecustomer flow demands:Table 3.6-1
Meter Size Type Manufacturer
IIme WHena:nE13/4” x 3/4
1 -1 /2”
2 1 1
3” Tru/FIa4” Tru/Flo
6” Tru/FloFire Service6" Protectus
(Shall be used forcombination of domestic andfire service
8” Protectus III Fire Service
(Shall be used forcombination of domestic andfire service
[me mmemi
Positive DisplacementPositive DisDlacementPositive Displacement
Positive DisolacementComCom
£ndCom
Neptune/BadgerNeptune/BadqiNentune Bad
WeItune/Badger
Neptune/Badger
Compound Neptune/Badger
Turbine meters shall be allowed for irrigation meters; not for domestic meters.
Venturi meters shall be allowed when recommended by City Water Utilities based onSingle Family Equivalent calculations.
Vaults are required for all meters greater than 2 in.
See Section 3.6.4 for Furnishing and Installing meters.
3.6.1 Number of Meters
One meter is required for each residential, commercial, or industrial service connection.
An apartment building, condominium, manufactured housing community, or mobile homepark may be considered a single commercial facility for the purpose of this section. The
City’s standard policy is that only one meter for domestic use will be furnished to eachlot. Exceptions to that policy are:
1)
2)
3)
Commercial, industrial or institutional sites shall have a separate irrigation meterfrom the domestic meter.
Multi-family developments with greater than 200 units shall be required to have two
domestic meters for redundancy and reliability of water service where each meter islocated on a different water main or separated by an inline valve.Multi-building sites where the configuration or size of the site makes a single meterlocation impractical or infeasible.
Submetering by the property owner to tenants of multi-family developments with aminimum of 5 units per building (or by condominium associations to member) shall be
11
Section 3
Water and Wastewater Criteria Manual
done at the owner’s expense with privately purchased and maintained meters and inaccordance with the Public Utilities Commission Chapter 24 Subchapter I.
3.6.2 SizingIn commercial and industrial projects, the design engineer shall consult with the owner orthe MEP engineer to identify proposed sizes and locations for domestic water meters,fire sprinkler connections and irrigation meters.
During Building Permit review, the City evaluates adequacy of meter size using TableE201.1, “Minimum Size of Water Meters, Mains and Distribution Piping Based on Water
Supply Fixture Unit Values (w.s.f.u.)” of the version of the International Plumbing Code
as adopted by the City (copy included herein as Table 3.6.2-1). The City’s BuildingPermit Plans Review uses the version of the International Residential Code as adopted
by the City, Table P2903.6, “Water-Supply Fixture-Unit Values for Various PlumbingFixture and Fixture Groups” (see Table 3.6.2-2) to estimate water supply fixture units(w.s.f.u.). To facilitate review of the proposed meter size, the design engineer shallsubmit a tabulation of water supply fixture units (w.s.f.u.); a sample tabulation is providedherein in Table 3.6.2-3.
Contact the Water Utilities Dept. regarding criteria for sizing fire-rated master meters.
When sizing water meters, the design engineer should be aware that, per CityCode, water and wastewater Impact Fees are based on water meter size, with thefollowing exceptions:
A. For multifamily developments of 8 or more units, Impact Fees are based on bedroomcount
B. For fire-rated master meters, Impact Fees are based on the equivalent meter sizethe City would require for domestic demands (except for multifamily developments of
8 or more units, in which case Impact Fees are based on bedroom counts).
C. For institutional developments like hospitals, dormitories, nursing homes or assistedliving facilities the Denton Water Utilities will need to be consulted as to the
appropriate methodology for sizing the meter.
D. For commercial or industrial sites that utilize large amounts of water in theirproduction process, the developer shall provide estimated peak daily demand. Meterto be sized to 1.25x peak daily demand.
Refer to Table 3.6.2-4, “Land Use and Service Unit/SFE Equivalencies.” Impact Feesare based on Single Family Equivalents (SFE’s). For example, Impact Fees for a 1-1/2”meter would be twice those for a 1 ” meter.
12
Section 3
Water and Wastewater Criteria Liar,ual
TABLE 3.6.2-1
2021 International Plumbing Code - TABLE E104.1MINIMUM SIZE OF WATER METERS, MAINS AND DISTRIBUTION PIPING
BASED ON WATER SUPPLY FIXTURE UNIT VALUES (w.s.f.u.)
EP STRIRIJTIONi
IVlllgV:gIll/11 lllVI IByF VFI I IPIVlIF NI 1 F NIKI I= lltlPPltal
METER ANSERVICE
PIPE
(inches)
PIPE
(inches)
PFeb+lllle K61lltCe lg JU IOI JUI DSI 60 80 100 150 200 250 300 400 50040
3/4
3/4
3/4
1/2a
3/4
1
2.5
9.5
32
32
32
80
80
87
151
151
87
275
365
2
7.5
25
32
32
80
80
87
151
151
87
275
365
1.5
6
20
27
32
70
80
87
151
151
87
275
365
1.5
5.5
16.5
21
32
61
75
87
151
151
87
275
365
0.5
3
7.8
8
20
27
31
64
79
83
87
196
229
0.5
2.5
6.5
7
17
22
25
56
69
72
87
174
201
0
2
5.5
5.5
13
16
17.5
45
54
56
87
144
160
4
11
13.5
30
45
54
84
117
128
87
258
318
3.5
9
10
24
34
40
73
92
99
87
223
266
1.5
4.5
5
10.5
12
13
36
43
45
86
122
134
3/4
1
1 -1 /2
1
1 -1 /2
2
1
1 -1/2
2
1 -1 /4
1-1/4
1-1/4
1 -1 /2
1-1/2
1 -1/2
2
2
2
13
Section 3
Water and Wastewater Cri{eda Mar:ua}
Note a: Minimum size for building supply is 3/4-inch pipe.
14
Section 3
Water and Wastewater Criteria Manuai
TABLE 3.6.2-1 (continued)
METER ANSERVICE
PIPE (inches)
i [1 STRIBUTI
PIPE
(inches)
0
MAXIMUM DEVELOPMENT LENGTH (feet)
Pressure Range 40 to 49 psi 40 60 80 IOO 150 200 250 300 400 500
3/4
3/4
3/4
1/2a
3/4
1
3
9.5
32
32
32
80
80
87
151
151
87
275
365
533
2.5
9.5
32
32
32
80
80
87
151
151
87
275
365
533
2
8.5
32
32
32
80
80
87
151
151
87
275
365
533
1.5
7
26
32
32
80
80
87
151
151
87
275
365
533
1.5
5.5
18
21
32
65
75
87
151
151
87
275
365
533
0.5
3
9
9.5
27
35
39
78
93
98
87
238
270
528
0.5
2.5
7.5
7.5
21
26
28
65
75
77
87
198
220
456
0.5
2
6
6.5
16.5
20
21
55
63
64
87
169
185
403
4.5
13.5
15
32
52
59
87
130
139
87
275
349
533
3.5
10.5
11.5
32
42
48
87
109
115
87
264
304
533
3/4
1
1 -1/2
1
1 -1 /2
2
1
1 -1/2
2
2
1 -1/4
1 -1 /4
1 -1/4
1 -1/2
1 -1 /2
1 -1 /2
2
2
2
2-1 /2
Note a: Minimum size for building supply is 3/4-inch pipe.
15
Section 3
Water and Wastewater Criteria Manua!
TABLE 3.6.2-1 (continued)
0
IVJ 14\XIIIBill JM F11FVHI omni;II HaIF I FIFI FdI :4 ffnnt\
METER ANSERVICE
PIPE (inches)
i [B STRIBUTI
PIPE
(inches)
e
PIIUS S IInn ItfalIIe in nII if 0 - r1111 tns I0 nII n 40 60 80 100 150 200 250 300 400 500
3/4
3/4
3/4
1/2a
3/4
1
3
9.5
32
32
32
80
80
87
151
151
87
275
365
533
3
9.5
32
32
32
80
80
87
151
151
87
275
365
533
2.5
9.5
32
32
32
80
80
87
151
151
87
275
365
533
2
8.5
32
32
32
80
80
87
151
151
87
275
365
533
1.5
6.5
25
30
32
80
80
87
451
151
87
275
365
533
0.5
3
9.5
10
29
35
39
82
94
97
87
247
272
533
0.5
2.5
8
8
24
28
29
70
79
81
87
213
232
486
5
18.5
22
32
68
75
87
151
151
87
275
365
533
4.5
14.5
16.5
32
57
63
87
139
146
87
275
365
533
4
12
13
32
48
53
87
120
126
87
275
329
533
3/4
1
1 -1/2
1
1 -1/2
2
1
1 -1/2
2
2
1 -1/4
1 -1/4
1 -1/4
1 -1/2
1 -1/2
1 -1/2
2
2
2
2-1 /2
Note a: Minimum size for building supply is 3/4-inch pipe.
16
Section 3
Water and Wastewater Criteria blanua!
TABLE 3.6.2-1 (continued)
STRIBU TION
nJlrAxlllm liM F)IEV Rtl OP IUll HaIT LENCiIIBH fteetlMETER ANSERVICE
PIPE (inches)
B PIPE
(inches)
Pressure Range Over 60 40 60 80 100 150 200 250 300 400 500
3/4
3/4
3/4
1
3/4
1
1 -1 /2
1
1 -1/2
2
1
1 -1/2
2
2
1/2a
3/4
1
1
1 -1/4
1 -1 /4
1 -1/4
1 -1 /2
1 -1/2
1 -1/2
2
2
2
2-1 /2
3
9.5
32
32
32
80
80
87
151
151
87
275
365
533
3
9.5
32
32
32
80
80
87
151
151
87
275
368
533
3
9.5
32
32
32
80
80
87
151
151
87
275
368
533
2.5
9.5
32
32
32
80
80
87
151
151
87
275
368
533
2
7.5
32
32
32
80
80
87
151
151
87
275
368
533
1.5
6
24
28
32
80
80
87
151
151
87
275
368
533
1.5
5
19.5
28
32
69
76
87
151
151
87
275
368
533
0.5
3
9.5
9.5
30
36
38
84
94
97
87
252
273
533
4.5
15.5
17
32
60
65
87
144
151
87
275
368
533
3.5
11.5
12
32
46
50
87
114
118
87
275
318
533
Note a: Minimum size for building supply is 3/4.inch pipe.
17
SectIon 3
Water and Wastewater Criteria Manual
TABLE 3.6.2-2
2021 International Residential Code
P2903.6 Determining Water6upply Fixture UnitsSupply loads in the building water-distribution system shall be determined by total load on the pipe being sized, interms of water-supply fixture units (w.s.f.u.), as shown in Table P2903.6, and gallon per minute (gpm) flow rates [seeTable P2903.6(1 )] . For fixtures not listed, choose a w.s.f.u. value of a fixture with similar flow characteristics.
TABLE P2903.6WATER-SUPPLY FIXTURE-UNIT VALUES FOR VARIOUS PLUMBING FIXTURES AND FIXTURE GROUPS
WATER-SUPPLY FIXTURE-UNIT VALUE(w.s.f.u.)TYPE OF FIXTURES OR GROUP OF FIXTURES
Hot 1 Cold I Combined
Bathtub (with/without overhead shower head)1.o 1 1 .o 1 1 .4
Clothes washer 1.o 1 1 .o 1.4
Dishwasher 1.4
1.5
0.5
1.4
3.6
2.6
2.5
2.5
1.4
Full-bath group with bathtub (with/without shower head) orshower stall 2.7
2.5
2.5
1.0
1.0
Half-bath group (water closet and lavatory)
Hose bibb (sillcock)’
Kitchen group (dishwasher and sink with/without garbagegrinder)1.9
1.0Kitchen sink
Laundry group (clothes washer standpipe and laundry tub)1.8
1.0
0.5
1.0
1.8
1.0
0.5
1.0
2.5
1.4
0.7
1.4
Laundry tub
Lavatory
Shower stall
Water closet (tank type)2.2 1 2.2
For Sl: 1 gallon per minute = 3.785 Um.
a. The fixture unit value 2.5 assumes a flow demand of 2.5 gpm, such as for an individual lawnsprinkler device. If a hose bit)b/sill cock will be required to furnish a greater flow, the equivalentfixture-unit value may be obtained from this table or Table P2903.6(1 ).
18
Section 3
Water and Waste’water Criieda Marlua:
Table 3.6.2-3
SAMPLE W.S.F.U. TABULATION
Water Supply FixtureFixture
Units (Each)
re uantity
Load Values_ in Total
Units
Total Fixtrrre
Water Closet (Public; Flush Valve)
Water Closet (Public; Flush Tank)
Urinal (Public; 3/4-inch Flush Valve)
Lavatory (Public)
Kitchen Sink (Hotel, Restaurant)
Service Sink
Shower Head (Private)
Total 162.4
Table 3.6.24
EXHIBIT F
WATER AND WASTEWATER FACILITIES
lnances
Single Family Equivalents (SFEs)Meter Size Typical Land Use
L AIIbI FI IJSyE AIFa IFEI :gEIRVI CF IJllKl IIK;FEIFaG-) U IVA\II- EN OIIne
From Section 26-218 of Citv of Denton Code of Ord
Meter Type
Residential - Single Family(Building less than 1,300 sq. ft./Fsitive Displacement 1 5/8" X 3/4" 1 lot size less than 6,000 sq. ft.
Fsitive Displacement 1 5/8" X 3/4" 1 Residential - Single Famil:
bsitive Displacement 1 3/4" X 3/4" 1 Residential / Commercial
lsitive Displacement 1 1 " 1 Residential / Commercial
lsitive Displacement 1 1-1/2" 1 Commercial
lsitive Displacement 1 2" 1 Commercial
Compound 1 3" 1 Commercial / Industrial
Compound 1 4" 1 Commercial / Industrial
Source: City of Denton Approved Meter Manufacturer's Specifications
NOTE: The total service units for multi-family apartment projects with eight or more units shall be determinedby multiplying the total number of bedrooms in the multi-family apartment project by 0.26 Single FamilyEquivalents (SFEs
19
Section 3
Water and Wastewater Criteria Manual
3.6.3 Location
Water meters and meter cans and vaults shall be placed within a City Right-of-Way,Public Utility Easement or Public Water Easement. Placement shall also satisfy the
following requirements:
A. Located as close as possible to the public water main.
B. Easily accessible to City of Denton employees.
C. Located in an unpaved area that does not conflict with vehicular or pedestrian traffic.
3.6.4 Furnishing and InstallingAll meters 2” and smaller shall be furnished and installed by City Water Utilities for fees
per the current Fee Schedule. All meter assemblies 3” and larger and their associatedvaults shall be furnished and installed by Contractor at their expense and inspected byPublic Works Inspection or City Water Utilities.
3.6.5 Details
Details of the meter can assemblies for meter sizes 2” and smaller are shown in the CityStandard Details.
Details of the meter vault assemblies for meter sizes 3” and larger are shown in the CityStandard Details.
3.6.6 Backflow Prevention
Backflow Prevention Assemblies (Double Check Valve Assembly unless other assembly
is specified elsewhere) are required in accordance with International Plumbing Code,2021 International Fire Code, 30 TAC 290, City of Denton Ordinances Chapter 28 ArticleXI. – Irrigation Systems, and:
A.At each dedicated fire line connection. If the building is located within 50 feet of theright-of-way or easement, the backflow preventer may be placed within the building.A flanged fire line valve shall be required to connect to the tee located on the main
line and a fire line valve shall be required outside the downstream side of the vault orROW line whichever applies.
After each meter of any site served by redundant domestic meters.
At facilities supporting Recreational Vehicle (RV) connections for the purpose offlushing waste tanks.
BC.
Backflow prevention devices shall be placed in vaults at the right-of-way or easement
line adjacent to the meter, except as afforded by 3.6.6(A) or as required by TCEQ to notbe vaulted
3.7 Water Main Horizontal and Vertical Alignment
The following guidelines should be followed by the design engineer in placement ofwater lines:
20
Section 3
Water and Wastewater Criteria Manual
A. In existing streets, water lines shall be placed in the pavement 2 feet inside of thecurb and gutter line intersection. For new residential development, water lines shall
be placed on the north and east sides of the streets, where possible, 2 feet inside of
the curb and gutter line intersection. See the City Standard Details.
B. All water lines shall be laid as straight as possible. Avoid excessive number of high
points and low points between cross street connections, as they trap air pockets.See Section 3.15.2 for placement of air release valves.
C. Minimum radius of curve and maximum deflection angle of pipe joints will berestricted to the manufacturer’s recommendation, after which the use of horizontal or
vertical bends will be required. Deflection of pipe shall only be permitted through jointdeflection; no bending of pipe is allowed.
D. Vertical bends shall be no greater than 45 degrees.
E. Except for transverse pipe crossings, no other utility shall be installed over, under orwithin 5 ft. horizontally of a water line.
F. Provide at least 2 feet of vertical separation between a water line and any utility orstorm drain crossing it
G. Be located no closer than 10’ to any building or structure.
Provide at least 2 feet of vertical separation between a water line and any utility or storm draincrossing it.
3-8 Highway Crossings
Crossings of State or County controlled roads shall require the review and approval ofthe appropriate regulatory agency. Crossings shall meet the requirements made by thecontrolling agency and by City of Denton Standards. In the event of different requirementlevels for the same item, the more stringent standard shall apply.
3.9 Railroad Crossings
The design engineer shall, prior to the design of any railroad crossing, contact theappropriate railroad company and regulatory agency and determine if there are anyspecial requirements. In the event City of Denton Design Criteria are more stringent thanthose of the Railroad Company or regulatory agency, the City’s standards shall apply.
3.10 Creek Crossings
Where water mains are laid under any flowing stream or semi-permanent body of water,such as a marsh or pond, or an identified environmentally sensitive area (ESA, seeDDC 7.4) the water main shall be installed in a separate watertight encasement pipe,with valves on each side of the crossing to allow the isolation and testing of that portion
of the water main to determine if there are any leaks and to facilitate future repairs.
21
Sec£ion 3
Water and Wastewater Criteria Manual
A primary consideration in the design of creek crossings is the prevention of soil erosionin the areas of trench backfill. The design engineer shall determine the need and limitsof any special embedment and determine and specify the limits for specialized backfills.
3. ff Tunneling, Boring, Jacking and Casing
Tunneling, boring, jacking and Casing are methods used for water line placement underrestrictive conditions when open-cut construction is not allowed. Only straight pipealignments for both horizontal and vertical alignment are allowed.
Design engineers should consider the location, size and depth of boring and receivingpits when choosing the beginning and ending stations for boring. A typical bore pit isbetween 35 and 40 feet in length to accommodate the boring machine and one joint of
pipe. Width of the bore pit can vary depending on the depth and size of pipe, with thenarrowest width being approximately 15 ft. Additional size and spacing requirements
may be required as outlined in DDC 7.4 when working adjacent to confirmed ESA. Thepreferred location for the bore pit is the lower elevation end of the bore; allowing anygroundwater and/or boring slurry to drain from the tunnel into the bore pit. The watercan then be removed by pumping.
Steel casing pipe, where required for open-cut or other than open cut installation, shallconform to City Standard Specification 33 05 07 Steel Casing Pipe, and have an insidediameter (ID) large enough to accommodate a carrier pipe of at least two (2) standard
sizes above the pipe being installed. Consult with Water Utilities Department Projectspecific design, sealed and signed by a Professional Engineer licensed by the State ofTexas
Carrier pipes may be PVC with external harness restrained joints (requires larger casingthan for pipe alone) or ductile iron with restrained joints. All carrier pipes shall beinstalled in accordance with the pipe manufacturer’s recommendations, properlyrestrained and supported with approved spacers and casing end seals. Pipe joint
restraint shall be achieved using only City approved pipe manufacturer externallyrestrained joint systems. Refer to Standard Detail U208A and the current City approvedMaterials Submittal List.
3. f2 Elevated Crossings
Elevated crossings are not permitted for water mains except for special cases approved
by the Director of Water Utilities. Design requirements for approved elevated crossingsshall be tailored to the specific project characteristics.
3. f3 Underground Utility Crossings
Where water mains are laid under or over another buried utility line or underground
facility (i.e., storm drain, culvert boxes, franchise utilities, etc.), special requirements maybe necessary for the protection of the water main. This table is not a replacement forseparation requirements for sewer and water lines as governed by 30 TAC 217 and 30TAC 290, respectively. Table 3.13-1 gives a breakdown of the provisions required fordifferent crossing situations.
22
Section 3
Water and Wastewater Criteria Manual
Table 3.13-1
Utility Crossing RequirementsWater
Utility
New/existingWater
New/existingSewer
New/existingWater
New/existingSewer
New Water
Crossing
Under
utility Line Size (in) I Separation (ft) I Special Requirement
less than 24 >= 2 None
Under less than 24 >= 2 None
I
Under 24 to 42 >= 2 None
Under 24 to 42 >= 2 None
Encased in 150+-psi
pressure class pipe
Encased in split steel
caslrlg
Encased in 150+-psi
pressure class pipe
Encased in split steel
casIng
Cased in steel pipe
Cased in split steel
pIpe
Cased in steel pipe
Cased in split steel
pIpe
Under
Under
Under
Greater than 42 >= 2
Existing
Water
New Sewer
Greater than 42 >= 2
Greater than 42 >= 2
ExistingSewermvF Under
Under
Greater than 42
e
>= 2
>=2
ExistingWater
New Sewer
Under
Under
Under
10 feet or greater
e
>=2
>=2
ExistingSewer
New/existingWater
New/existingSewer
New/existingWater
New/existingSewer
10 feet or greater >=2
>= 2
>= 2
>= 2
1 >= 2 1 None
Over
Over
I Over 1
Over
less than 24 None
less than 24 None
None
None
24 or greater
24 or greater
To minimize crossing impacts, crossings must be perpendicular, if possible.
Utility crossing with less than 2’ of separation require a variance (which will includespecial requirements) after providing a thorough analysis detailing physical andeconomic factors involved .
Pursuant to City Ordinance Chapter 25 Section 25-80- Facility Size and Locations, allright-of-way user facilities are required to maintain a minimum separation of twenty-four (24) inches from all city utility system facilities. If a right-of-way user mayencounter a hardship due to this requirement, the right-of-way user may request avariance to the minimum separation requirement in writing and in advance with the
23
Section 3
Water and Wastevva£er Criteria Manual
permit application. Any exception granted will be subject to the City Engineer's
approval or denial with the permit application, and only applicable to a single issuedpermit
Split steel casing shall follow sizing requirements of pressure rated casing.
See City Standard Specification Section 33 05 07 Steel Casing Pipe.
Casing spacers shall be placed not more than 5’ apart.
Encasement shall be extended a minimum of 3 feet beyond the edge of the utility orfacility to be crossed. Water mains that cross utility lines in private easements mustadhere to the requirements of the easement owner as well as those listed above.
3.14 Fence or Wall Crossings
Water mains should be routed to avoid entering private property. In circumstances
where it is impractical to avoid doing so, provisions are required to allow City staff to
inspect, maintain and repair its infrastructure. Water mains crossing fences will require avariance by the City Engineer in consultation with the Director of Water Utilities after
thorough consideration of the physical and economic factors involved. Variances mayrequire additional provisions beyond this Manual.
Water mains crossing under privacy fencing (wood, chain-link, or plastic) shall notrequire any special protection.
Water mains crossing under other types of fencing will require the fence to beconstructed of easily removable panels or have gates that can be removed from theeasement.
Water mains may not cross under retaining walls.
3. f5 Existing Water Main Replacement
Whenever an existing main is to be replaced by a new main use the following guidelinesfor alignment and design:
1 ) The new line should be located as near as possible to the existing line while allowing
the existing line to remain in service until the new line is ready to be put into service.2) if the existing line is in or next to a roadway, the new line should be placed underexisting pavement, not behind the curb in the parkway area.3) The new line should be designed to utilize the existing metering locations where
possibleThe size of the new line should match the size of the existing line. If the existing line is anon-standard size (i.e., 6” or 10”) than the new line should be sized for the next largerstandard size. The design engineer shall perform field investigations to determinepavement condition over the existing main. The pavement may have been patched dueto breaks in the existing main over the years. Based on field investigations, the design
engineer shall include additional quantities for pavement replacement, if necessary.
24
Section 3
Water and Wastewater Criteria Manua:
3.16 Methods of Connection
3.16.1 Pressure Zones
The City of Denton’s Water Distribution System is divided into several water pressurezones to ensure even water pressure gradients. Prior to the design of connection pointsbetween a proposed main and any existing main, the design engineer shall investigateand determine if the proposed water main crosses the boundary between different
pressure zones.
Even though physical connections of water pipes exist between pressure zones, theyare designed with valves which are closed at the boundary points so that each pressurezone is isolated. Proposed mains that approach pressure zone boundaries shall be
designed to loop within their designated pressure zones and with no or minimum lengthsof dead-end mains.
Connections between pressure zones must be approved by the City of Denton, and mayrequire pressure reducing valve stations. The design engineer can determine thepressure zone boundaries by consulting the record drawing water maps which show the
designated closed valves between pressure zones and by contacting Water Utilities. SeeFigure 3.16.1-1 for a Pressure Zone Map.
25
Section 3
Water and Wastewater Criteria Manual
FIGUU blCITY OF DEN'rON
WAll.R SYS I t\II'Icon)gII) }'RBSURt PLAn\ tJ
1.1'GIN:),+ bqlrHF++ UU
HEatf Let
tIa San hrT
aBU Cq LPtl
-- quI=nqabqez
C+Pr+Ini
CHI Ctlq
huvu•+ew)
aRatebeIF ISIt !brd#Hru+++
Figure 3.16.1-1 2018 Water Master Plan Pressure Zone Map
26
Section 3
Water and Wastewater Criteria Manual
3.16.2 Tapping Sleeve and Valve
Tapping sleeves with tapping valves shall be used whenever possible for connections toexisting mains to avoid interruption of water services. See Figure 3.1 in Drawing PIAZ13of the City Standard Details.
A. Size on size taps are allowed up to 12.”
(Example: 12” X 12”)
B. Taps on 16” and larger pipes must be approved in writing in advance by the Directorof Water Utilities, and at least one standard pipe size smaller than the pipe being
tapped. See Figure 3.2 in Drawing PIAZ13 of the City Standard Details.
(Example: 16” X 12”, 16” X 8“ and 16” X 6” taps are allowed).
C Connections to fire hydrant leads are not allowed.
3.16.3 Cut-In Connection
On occasions when connecting to an existing main, it may be desirable to have anadditional valve on the existing main. In this situation, the design engineer should
consider using a cut-in connection with a tee and valve being cut into the existing main.See Figure 3.4 in Drawing PIAZ14 of the City Standard Details.
3.16.4 Main Extensions
A new valve shall be installed at the point of connection for water main extensions. Thiswill facilitate the testing and chlorination of the new main prior to its placement into
service. See Figure 3.5 in Drawing PIAZ14 the City Standard Details.
3. f 7 Valves
3.17.1 Isolation Valves
3.17.1.1 Location
Isolation valves shall be provided to allow for the proper operation and maintenance ofthe water distribution system, and to ensure water quality can be maintained to eachindividual water customer connected to the system.
The location of valves needs to properly address the ability of the Department of WaterUtilities to remove a water line from service to perform necessary repairs, whileminimizing the interruption of service to the least number of customers and to fireprotection. Isolation of any given section of water line should generally be able to beaccomplished by closure of the least number of valves, as would generally be expectedunder good engineering design practices and utility engineering standards. The
Department of Water Utilities reserves the right to require changes to proposed designsto satisfy these objectives.
The design engineer shall place valves on proposed water mains so they may be easilylocated in the future by operations and maintenance crews.
27
Section 3
Water and Wastewater Criteria Manual
The following guidelines should be used by the design engineer in placement of isolation
valves on proposed water mains:
A. Two valves are to be installed at every tee location, one Hanged to the branch of thetee and the other a mechanical joint connection on one of the two runs of the tee.See Figure 3.6 in Drawing PIAZ15 of the City Standard Details. Three valves are to
be installed at every cross location, each a mechanical joint connection.
B. Valves for line sizes 12” in diameter or less should not be spaced any farther apartthan 1,000 feet. For city blocks that are longer than 1,000 feet between streetintersections, placement of a valve will be required between street intersections.
C. Valves should be generally located so that no more than four (4) valves are requiredto isolate a section of main. See Figure 3.7 in Drawing PIAZ15 of the City StandardDetails. For mains larger than 12” in diameter, valve spacing and placement shall besubject to alternate criteria approved by the Director of Water Utilities.
D. All fire hydrant leads are to be designed with a valve that is f]anged to the main line.
3.17.1.2 SpecificationsRefer to Table 3.17.1.2-1 and Standard Specifications 33 14 20 Resilient Seated
(Wedge) Gate Valves and 33 14 21 AWWA Rubber-Seated Butterfly Valves
Table 3.17.1.2-1
Isolation Valve Requirements
Size 1 4 in. - 12 in. 1 16 in. - 20 in. 1 24 in.30 in.36 in. or larger
Gate Valve I Gate Valve I Gate Valve
(AWWA c509 1 (AWWA c515 1 (AWWA c515
resilient-seat) I resilient-seat) I resilient-seat)
Gate Valve
(AWWA C515
resilient seat)
Gate Valve (AWWA
C515 resilient-seat) orbutterfly, to be
determined by City on acase-by-case basis
Type
Vertical or
horizontal: to be
determined by Cityon a case-by-casebasis
Orientation Vertical Vertical Vertical
Vertical or horizontal; to
be determined by City ona case-by-case basis
Gear
OperatorRequiredVaultRequired
BypassRequired
No
No
No
No
No
No
Yes
Yes
No
Yes Yes
Yes
Yes
Yes
Yes
28
Section 3
Water and Wastewater Criteria Manual
3.17.1.3 Details
Refer to Drawings W1 04, W105, W106A, W106B, and W601 of the City StandardDetails.
3.17.2 Air Release Valves and Air / Vacuum-Air Release ValvesFor water mains less than 16” diameter in certain situations where the topography,remoteness, or some other hydraulic factor necessitates it, air release valves arerequired at local high points to facilitate automatic release of accumulated air.
For 16” and larger mains, the City requires air / vacuum air release valves at local highpoints to facilitate automatic release of accumulated air and to facilitate automaticprevention of vacuum conditions within the line. See Drawings W801 and W802 of the
City Standard Details.
3.17.3
3, f 8 Dead-end Mains
Dead-end main situations should be avoided whenever possible.
In lieu of dead-end mains, the design should loop through public right-of-way or adedicated public utility easement (with adequate assurance of access and fencingprohibited) to another nearby water main using the same size pipe.
If a dead-end main situation is unavoidable, it shall be designed so that it may be
periodically flushed of stagnant water by locating a fire hydrant or other flushing devicenear the main’s end and past the last service connection.
3. #9 Fire Hydrant Locations and Coverage
The design engineer should locate fire hydrants as close as possible to streetintersections, but outside of the curb radius. This positioning of fire hydrants provides
coverage along several streets. When spacing requirements necessitate the installationof fire hydrants between street intersections, they should be placed at the projection oflot lines between property owners. For main replacement projects in establishedneighborhoods, fire hydrants should be designed as close as possible to the old firehydrant location, provided coverage is adequate. Neighborhood residents are familiar
with the fire hydrant being at that location and normally expect a replacement firehydrant to be placed at the same location. Fire hydrants are not to be installed closerthan nine (9) feet to any wastewater main, manhole or appurtenance.
Fire hydrant spacing shall comply with the 2021 IFC Appendix C Fire Hydrant Locationsand Distribution, and be easily accessible by City staff and First Responders. See CityStandard Details W401 A and 401 B, and Standard Specifications 33 1440 Fire Hydrants.
3.20 Requirements for Abandoning Water Mains
29
Section 3
Water and Wastewater Criteria Manual
The design engineer should note the limits and appropriate conditions for the
abandoning of existing water mains which are to be replaced by the construction of anyproposed water mains.
The design engineer should also make allowances in the design to provide for theexisting and proposed mains to be in service simultaneously until all customer services
are transferred from the old main to the new main with minimum interruption of service.
If the construction of a proposed main necessitates the abandoning of the existing mainprior to the new main's placement into service, then provisions for a temporary watermain with services must be addressed by the design.
Typically, abandoned lines may be left in place with only the ends being plugged withgrout or concrete. However, the City may require special abandonment actionsincluding, but not limited to, filling the abandoned water main with grout, removal andproper disposal of all above ground appurtenances, and removal and proper disposal ofthe abandoned pipe.
3.20.1 Replacement MainsOn mains being abandoned, the design engineer shall note and locate points of cut and
pIug as close as possible to the main that remains in service. (See Figure 3.9 inDrawing PIAZ16 of the City Standard Details).
3.20.2 Extension Mains
If a design requires an existing main to be cut by a connection with a proposed main,then a cut and plug is to be specified behind the connection point. (See Figure 3.10 inDrawing PIAZ16 of the City Standard Details).
3.20.3 Fire HydrantsFire hydrants located on mains being abandoned shall be removed and delivered to theCity of Denton Water Utilities Department.
3.21 Flushing and Disinfection
Prior to making permanent connections to the distribution system, water distributionmains, valves and appurtenances shall be adequately flushed and disinfected inaccordance with the most current revision to AWWA C651, and bacteriological testingshall be completed to meet the standards established by the Water Utilities Department
and Chapter 290 of the Texas Administrative Code (30 TAC 9290). Additionally, heavilychlorinated water shall be flushed from all segments of the newly constructed mainsbefore final connections are made.
Before commencement of construction of water distribution infrastructure, the Contractoror engineer shall submit a flushing and disinfection plan for review by the Department ofWater Utilities. At a minimum the plan shall describe:
AB,
C
Flushing proceduresHydraulic calculations to demonstrate adequate flushing velocities, ordemonstrate conformance with the conditions outlined in AWWA C651 Table
3The method of chlorination
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D. Bacteriological sampling plan
E. Dechlorinating procedures (Ref. AWWA C655)F. Disposal of chlorinated water and methods used to ensure discharges tosurface waters or storm sewer systems do not exceed 0.1 mg/L total chlorine.
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Section 4 – Wastewater Design Guidelines
4. i General
It is the responsibility of the design engineer to ensure the final design of a sewer main isin conformance with the following:
A.
BC
DEFG.
Texas Administrative Code (TAC) Title 30, Part 1, Texas Commission on
Environmental Quality (TCEQ) – Rules, Ch. 217, “Design Criteria for DomesticWastewater Systems”Public Utilities Commission Rules Chapter 24
City of Denton Code of Ordinances and Denton Development Code (DDC)This Manual
The City of Denton’s Standard Details and Standard SpecificationsCurrent City of Denton Wastewater Master PlanAmerican Water Works Association (AWWA) Standards
4.2 Estimated Wastewater Flows
A For sewers in new developments, sewer lines and lift stations shall be designed toaccommodate the projected buildout flows from all residential, commercial, industrial,
or institutional sources upstream of the proposed sewer improvement. Figure: 30TAC 6217.32(a)(3) Table B.1. - Design Organic Loadings and Flows for a NewWastewater Treatment Facility (see excerpted information in Table 4.2-1) shall beused as a guide to generate wastewater flows. However, minimum flow capacity forsizing of sewers for peak flow condition shall not be less than the results of thefollowing calculation procedures:Delineate the wastewater drainage area that will drain into the sewer main or liftstation. Include all upstream offsite areas.
For the development site, use the following design parameters:Table 4.2-1 to generate the wastewater loading by type of use.3.2 capita per lot for single family.
a
b
,. 2.5 capita per unit for multifamily.
d. Apply a 4.0 multiplier to the average daily flow to determine the peak flow.For undeveloped upstream areas, use the following design parameters:4 lots per acre
3
3.2 capita per lot.
a
b
,. Average daily flow of 100 gal/capita/day.d. Apply a 4.0 multiplier to the average daily How to determine the peak flow.
For developed residential upstream areas, use the following design parameters:
Count number of single family lots.a
Obtain number of multifamily units (available through DCAD)b
3.2 capita per lot for single family.2.5 capita per unit for multifamily.
For developed non-residential upstream areas, use the following design
C
d
e. Average daily flow of 100 gal/capita/day.f. Apply a 4.0 multiplier to the average daily flow to determine the peak flow
parameters:
1
4
2
5
a. Average daily flow of 1500 gpd/acre.
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b,Apply a 4.0 multiplier to the average daily How to determine the peak flow
For replacement of existing sewers and construction of parallel sewers for additional
capacity, wastewater flow data will be provided by the City from data generated by Citysewer shed computer models.
TABLE 4.2-1
* City of Denton requires usage of the highest number of theTCEQ ranges.
4.3 Separation Distances between Wastewater Collection System Pipes andManholes and Public Water Supply Pipes
Wastewater mains and manholes shall be separated from water mains as set forth inTexas Administrative Code (TAC) Title 30, Part 1, Texas Commission onEnvironmental Quality (TCEQ) Rules - 30 TAC $217.53.d Separation Distances.
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4.4 Size and Slope of Sewers
After the design engineer has determined the wastewater flows per Section 4.2, the
sewer size can be determined using the following criteria. However, no sewer, other thanservice laterals and force mains, shall be less than 8 inches in diameter.
The size and grade of the proposed sewer shall be evaluated by Manning’s Equation.
\1= 1.49 (R) o-67 (S) o'50n
Where:
V = velocity (feet per second)n = Manning’s coefficient of roughness;minimum 0.013
R = hydraulic radius (feet)
S = slope of energy grade line (feet perfoot)
Proposed sewers shall be designed with slopes sufficient for 3.0 feet per second (fps)velocity, with a minimum velocity required of 2.0 (fps). The minimum acceptableManning’s “n” factor for design shall be 0.013, which takes into consideration the slime,
grit and grease layers that will affect hydraulics or hinder flow as the pipe matures. Thesewer pipe grades shown in Table 4.4-1 are based on an “n” value of 0.013 and are the
minimum acceptable slope for sewer lines.
Table 4.4-1
Minimum and Maximum Pipe Slopes
Size of Pipe inInches I.D Minimum SlopeIn Percent Maximum Slope inPercent
Capacity FlowingFull at Min. Slope
(MGD)
8
10
12
15
18
21
24
27
30
33
36
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Section 4
Water and Wastewater Criteria Manua:
The capacity of the sewer pipe flowing full shall be computed by the following equation:
C = 0.299 (D) 2-67 (S) o'50n
Where C = capacity (million gallons per day)n = Manning’s coefficient of roughness; minimum 0.013
D = inside diameter (feet)S = slope of the energy grade line (feet per foot)
Sewer mains shall be designed to convey peak flow at no more than 80% if full pipecapacity at system buildout.
4.4.1 High Velocity ProtectionWhere velocities greater than 10 fps will occur when a pipe flows full, based on
Manning’s Equation and an “n” value of 0.013, restrained joint pipe or external restraintsystems must be utilized.
4.5 Sewer Main Depth
Minimum depth for the design of sewer mains shall be determined by providing a two
percent grade for the lateral from the center of the house or building to the center of theproposed main and including an additional two foot drop. Therefore, for a house 100feet from the proposed sewer main, the designed depth of the main shall be at least 4.0feet below the finished floor elevation of the house since:
2 feet + (2% of 100 feet) = 4.0 feetThe lateral also must have at least two (2) feet of cover at its shallowest point. The
design engineer is responsible for ensuring sufficient depth and grade is maintained toserve all building sites in the sewer shed.
4.6 Recommended Cover
Recommended cover for all sewer mains is four (4) feet to six (6) feet. Minimum covershall be 3.5 feet. Any main approved to have less than minimum cover shall be encasedin Class “G” embedment. See Drawing U204 of the City Standard Details.
When establishing depth for proposed wastewater mains, design engineers shallconsider the impact of proposed water and drainage improvements especially on servicelaterals that cross those improvements to connect to the wastewater main .
4.7 Sewer Alignment
Design engineers shall be guided by the following in the alignment of wastewater lines:
A.
B.
C
For new construction in areas not served, sewer mains shall be laid straight betweenmanholes. No horizontal or vertical bends are allowed between manholes.
Avoid shifting mains from one side of the ROW to the other side of the ROWbetween street intersections
Where the bypass of existing flows is feasible, it is recommended that replacementmains be constructed horizontally in the same trench.
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D. Except for pipe crossings, no franchise utility shall be installed within 5 ft of a sewermain
4-8 Sewer Laterals
Laterals may not serve more than one lot.
Minimum lateral sizes from the sewer main to the public cleanout are:
A. 4” minimum for single familyB. 6" minimum for residential duplex, triplex, and quadplex
C. 6” minimum for local retail, light commercial, apartment, manufacturing and industrial
Single-way clean-outs shall be provided on laterals at the public easement or Right-of-Way line. Double-way cleanouts are not allowed. See Drawings S403 and S404 of theCity Standard Details.
Manholes shall be provided for lateral connections when the lateral pipe diameter isequal to the main sewer pipe diameter or the lateral is 8-inch diameter or larger.
Laterals shall be constructed to the property line and shall be located at a point five (5)feet downstream from the center of the lot on unimproved property. For improved
property, design engineers should use technical judgement in lateral placement.
Preferred grade for lateral construction is 2%. Laterals shall not be designed with lessthan 1% grade.
4.9 Gravity and Force Main Sewer Pipe Material
Gravity and Force Main sewer pipe shall meet the following criteria unless specialcircumstances require an alternative and is approved by the Director of Wastewater
Utilities
Table 4.9-1
Application Pipe Material
8 in. through 12 in
pvc –ASTlm34, aM
HDPE – ASTM D3350, DR-17
PVC – ASTM D3034, SDR 26
18 in. through 24 in PVC – ASTM F 679. PS115
Fiberglass Reinforced Plastic – ASTM D3262
6 in. through 60 in,HDPE – ASTM D3350. DR-13.5
DIP – AWWA C150/C151, CL52 or PC 350, epoxy interior lining
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For gravity sewer pipe sizes over 24” in diameter, design calculations and pipe selectionshall be submitted by the development design engineer for review; approvals will beprovided on a project specific basis.
Force main sewer pipe shall be designed to meet the working and surge pressure
requirements of the specific application. Design calculations and pipe selection shall besubmitted by the development design engineer for review.
Different pipe materials shall not be mixed between manholes. If it is anticipated that amixing of materials will occur, the design engineer shall design a manhole at the point oftransition of pipe materials. For previously placed stub-out of a material other than PVC
pipe, design engineer shall add a note to the plans calling for removal of the stub out or
change the material of the proposed pipe for that section of pipe between manholes.
4.10 Sewer Pipe Embedment
The types of embedment and backfill for sewer mains are shown in Drawings U201,U202, U203A and U203C of the City Standard Details. Embedment requirements shall
be based on sewer mains under proposed pavement, unpaved areas and existing
pavement.
4.11 Manholes
Manholes constructed on existing or proposed sewer lines shall be sized as follows:
Table 4.11-1
Pipe Diameter
8’' through 12’
15“ through 27”
30” through 36’
Manhole Diameter
EnId
(For depths greaterthan 12 ft., use 5.0 ft.
5.0 ft.
6.0 ft
Special manholes shall be designedfor mains larger than 36” diameter pipe.
The types of manholes allowed by the City are shown in Drawings S101, S102, S103and S107B of the City Standard Details.
Generally, manholes shall be stationed on the main run, and where known, the stationsof the side mains should also be indicated. When connecting a proposed main to an
existing main at a manhole, the connection shall have the top inside elevation of theoutfall main level with the top inside elevation of the proposed main.
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4.11.1 Manhole Locations
Manholes shall be provided at the following locations to facilitate maintenance, cleaning,and inspection:
A
B.
C
DE.
F.
G
H.
1.
J.
At the location of lateral connections that are 8“ in diameter or larger.At 500 feet intervals on sewer mains 15” diameter or smaller; at 800 feet internals on
mains 18” diameter through 30” diameter; at 1,000 feet intervals on mains 36”
diameter through 48” diameter; and at 2,000 feet for 54“ diameter and larger.At all locations where pipe diameter or pipe material changes.At all locations where the horizontal or vertical alignment of the sewer main changes.At the ends of all mains with service connections. Two ends of a main may not becombined in one manhole.
If the main line is less than 150 ft. long and does not contain any service
connections, then a Sanitary Sewer Mainline Cleanout may be used. See DrawingS402 of the City Standard Details.At the end of any pipe segment at least 150 feet long.Sewer service laterals are to be connected to the sewer main line and not into amanhole unless it is a size on size connection
Manholes shall not be placed in sidewalks, pedestrian ramps, driveway approaches,
or in the bottom or on the slopes of a drainage channel or drainage structure.
Manholes shall be kept a minimum of 30 feet from any railroad track.
4.12 Highway Crossings
Crossings of State or County controlled roads shall require the review and approval ofthe appropriate regulatory agency. Crossings shall meet the requirements made by thecontrolling agency and by City of Denton Standards. In the event of different requirementlevels for the same item, the more stringent standard shall apply.
4.13 Railroad Crossings
The design engineer shall, prior to the design of any railroad crossing, contact theappropriate railroad company and regulatory agency and determine if there are any
special requirements. In the event City of Denton Design Criteria are more stringent thanthose of the Railroad Company or regulatory agency, the City’s standards shall apply.
4. f4 Tunneling, Boring, Jacking and Casing
Tunneling, boring, jacking and casing are methods used for sewer line placement underrestrictive conditions when open cut construction is not allowed. Only straight pipe
alignments for both horizontal and vertical alignments are allowed.
Design engineers should consider the location, size and depth of boring and receivingpits when choosing the beginning and ending stations for boring. A typical bore pit is
between 35 and 40 ft. in length to accommodate the boring machine and one joint ofpipe. Width of the bore pit can vary depending on the depth and size of pipe, with thenarrowest width being approximately 15 ft. The preferred location for the bore pit is the
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lower elevation end of the bore; allowing any groundwater and/or boring slurry to drainfrom the tunnel into the bore pit. The water can then be removed by pumping.
Steel casing pipe, where required for open-cut or other than open cut installation, shallconform to City Standard Specification 33 05 07 Steel Casing Pipe, and have an inside
diameter (ID) large enough to accommodate a carrier pipe of at least two (2) standardsizes above the pipe being installed.
Force mains through casings shall follow the same requirements as are laid out for watermains in section 3.11 of this manual.
4.15 Underground Utility Crossings
The requirements of Section 3.13 of this manual shall govern the crossing ofunderground utility lines by wastewater mains.
4.16 Fence or Wall Crossings
The requirements of Section 3.14 of this manual shall govern the crossing of fences orwalls by wastewater mains.
4.17 Creek Crossings
When a sewer main crosses a creek or channel, the design engineer must evaluate thecondition of the creek bed and ensure erosion control is provided. Backfill material and
minimum construction criteria are shown in the City Standard Details S701 and S702.These criteria include creek bed soil and condition, as well as presence of exposed rock.When working in these areas, minimize storage of soil, materials, and equipment near
floodways and waterways.
4.18 Siphons
For creek or channel crossings where a Low Water Channel Crossing is not feasible,design of an inverted siphon crossing is permissible when approved by the Director ofWater Utilities. Inverted siphons shall not have less than two (2) barrels, with a minimumpipe size of eight (8) in., and shall be provided with necessary appurtenances for
convenient flushing and maintenance. Access structures are required at each end of thesiphon with adequate clearance for maintenance and cleaning purposes. Bank andchannel stabilization may be required to protect the crossing lines and casing of thecarrier pipe may be required to meet environmental or other restrictions.
4.19 Abandonment of Sewer Mains
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The design engineer should note the limits and appropriate conditions for theabandoning of existing wastewater mains which are to be replaced by the construction ofany proposed wastewater mains.
The design engineer should also make allowances in the design to provide for the
existing and proposed mains to be in service simultaneously until all customer servicesare transferred from the old main to the new main with minimum interruption of service.
If the construction of a proposed main necessitates the abandoning of the existing mainprior to the new main’s placement into service, then provisions for a temporarywastewater main with services must be addressed by the design.
Typically, abandoned lines may be left in place with only the ends being plugged withgrout or concrete. However, the City may require special abandonment actionsincluding, but not limited to, filling the abandoned wastewater main with grout, removaland proper disposal of all above ground appurtenances, and removal and properdisposal of the abandoned pipe. In situations where a manhole is being left in serviceeven though one or more lines into the manhole are being abandoned, the abandoned
line shall be cut and plugged outside of the manhole. However, if the City determinesthat the pavement is in good condition the City may allow the abandoned line to be
plugged from inside of the manhole.
4.20 Abandonment of Manholes
If a manhole as well as the sewer main is to be abandoned, the method described in
Abandonment of Sewer Mains, above, along with the minimum guidelines shown inDrawing S105 of the City Standard Details, shall be used.
4.21 Lift Stations
The need to construct a lift station should be determined only after a thorough analysisof the physical and economic factors involved. A Preliminary Engineering Report isrequired, which lists all factors and adheres to current state regulations. The Cityreserves the right to review each proposal and determine whether there is enough merit
to justify a lift station. Any lift station located in the City of Denton CCN must adhere tothese requirements.
4.21.1 Preliminary Design Submittal
A preliminary design submittal is required for each lift station proposed. The submittalshall include a written report and a map prepared by a Professional Engineer licensed bythe State of Texas
A. The plans submitted shall contain the following information, as a minimum:Be to scale, with the scale indicated.A north arrow
A location map.
Delineation of the boundary of the proposed development.
Delineation of the boundary of the sewer shed in which the development lies.The area in acres of the development.The area in acres of the sewer shed contributing to the Lift Station.
12
3
4567
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8. The proposed land use or uses for the development.9. The proposed land use or uses for the sewer basin.
10. The proposed lift station site.11. The proposed force main routing and size.12. Delineation of the one-hundred-year flood plain and Environmentally SensitiveAreas (ESAs).13. Location and size of the existing collection system at the tie-in point.
14. Contour lines (2-foot intervals).15. Show how storm drainage is taken off site.16. Property lines.
B.The written report shall include the following information:1. A general narrative about the proposed development and the circumstances thatwarrant a lift station
2. Influent hydraulic calculations showing:Area in acres of the sewer basin and the development.The area of each proposed land use for the development and for the
projected land use(s) for the basin.The design flow for the basin and the development.The maximum flow for the basin and the development.Elevation of the proposed lift station site.
The elevation of the proposed discharge point of the force main.
a
b
C
d
e
f
3. Preliminary wet well volume calculations.4. Preliminary force main size.5. Cost estimates for proposed lift station(s) and force main(s), and cost estimates
for a gravity line in lieu of the lift station if possible.6. Ground water levels in proposed site areas.
4.21.2 Site Layout
A. Station Siting. The following are the minimum criteria for station sites.
1. The station shall be protected from the 100-year flood and shall be accessibleduring a 25-year flood.
2.The station should be located as remotely as possible from populated areas.
The entire station site shall be completely enclosed with an eight (8) feet. high,opaque concrete or masonry wall, with an opaque sliding gate with a minimumwidth of sixteen (16) feet. on track flush with the ground. All shall be of anarchitectural style and colors blending with the development architecture, asapproved by the city.
The station shall have a minimum 16’ wide drive approach and be accessible by City of Denton
service trucks without requiring vehicles to turn after entering the drive approach to the station.3. The station will include an approved odor control system.
4. The station site and its access shall be dedicated to the City as City property.
5. The station site shall be located so it may serve as much of the entire sewerbasin as possible. This may require the station to be located off-site of thedevelopment. When it is required the station serve a larger area than the
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proposed development, the developer may enter into a pro-rata contract with the
City to be reimbursed the cost of excess capacity as other developments tie tothe system.On-site generator must have an unobstructed 36” buffer on all sides accessible
by City service vehicles.
6.
B. Wet Well/Dry Well Arrangement
1. Orientation shall consider the routing of incoming sewers and force main.
2. Orientation shall allow a two-ton vehicle to directly access the wet well or the drywell, forwards and backwards.
3. Wet wells and dry wells shall be separated by at least a water and gas tight wall
with separate entrances.
4. Wet wells shall have sloped bottoms to avoid excess sludge deposits.
5. The wet well shall have a lockable aluminum door with an aluminum frame and
safety grating. The minimum opening size shall be 4’ x 6’ with two doors largeenough to adequately maintain the wet well. Door and frame shall be Bilco
Type K, KD or an approved equal.
6. The dry well or valve vault shall have a lockable aluminum door with analuminum frame and safety grating. The minimum opening size shall be 2’x 3’
or large enough to adequately maintain the dry well or meter vault. Door andframe shall be Bilco Type K, KD or an approved equal.
7. The wet wells, dry wells, manholes, valve vaults and meter vaults, includingdecks, shall all be cast in-place concrete only. No other materials are
acceptable. See City Standard Specification 33 05 64 Concrete Wet wells, ValveVaults, and Appurtenances for Lift Stations.
8. The coating for the wet well exterior and interior walls shall be coated asspecified in 4.21.2.C and D below, respectively.
9. The wet well shall be hydrostatically tested to the top of the wet well for 48-
hours prior to placing the lift station into service. Only losses due to evaporationwill be acceptable.
10. Provisions shall be made to remove water from the dry well, valve vault or meter
vault without allowing gas or water from the wet well into these structures.
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C. Exterior Walls (below grade, to be backfilled)
Table 4.21-1
Surface Preparation Coating Systemi !aBEIE1
Polyamide Epoxy - CoalTar
Clean and Dry 8 - 10 mils in two coatsfor a total of 16.0 to 20.0
dry mils
D. Interior Walls (Thick Film System)
Table 4.21-2
Surface Preparation Coating System
Finish
Brush-off Blast
Cleaning Mortarclad0.25 in,Perma-Shield
100 - 125 dry mils
In addition to this coating system, the lining products listed inDrawing S101 of the City of Denton Standard Details and StandardSpecification 33 01 40 Liners for Sanitary Sewer Structures are acceptable.
E. Site Access
1. Access will be provided by an all-weather surface of flex-base or better from apublic street to the station site.
2. Access shall be functional during a 25-year flood. The road surface shall beabove the water level caused by a 25-year return period storm.
3. Every station more than 100 feet from a public street requires a turn-aroundadjacent to the lift station, sized large enough to accommodate a City servicetruck with generator.
F. The equipment rack shall not obstruct vehicle access to the wet well or the dry well;the location must be approved during the review process. It shall be placed at an
easily accessible elevation and include a canopy.
G. Site inside the fence shall be an all-weather surface, such as 3% in. crushed rock orflex-base.
H. Passive ventilation shall be screened to prevent insect access to the wet well.Minimum air vent shall be 4-inch diameter. Vent outlet shall be at least 1 foot above
the 100-year flood elevation.
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4.21.3 Hydraulic DesignA. Influent Flow
The preliminary design report shall include the design flow and the maximum flow forthe development and the sewer basin. The design flow shall be calculated inaccordance with TCEQ rules. Refer to Section 4.2 Estimated Wastewater Flows
herein for maximum flow calculations.
B. Pump Capacity
1. Definition
Firm pumping capacity is the pumping capacity of the station with the largest
pump out of service.
2.The firm pumping capacity shall be greater than the maximum flow for the entiresewer basin. If the sewer basin is significantly larger than the proposeddevelopment and it is not feasible to design for this flow, the firm pumpingcapacity may be designed to handle a portion of the basin with approval from theDirector of Water Utilities.
3. The pump curves shall be selected so the pumps will run near the best efficiencypoint during normal operating conditions. The selected curves shall also be such
that the pumps do not approach shut-off head when they are runningsimultaneously.
System head curves, pump curves and head calculations shall be submitted.Calculations and pump curves at both minimum (all pumps off) and maximum(last normal operating pump on) static heads, for a C value of both 100 and 140,must be provided for each pump and for the combination of pumps with modifiedpump cuives.
C. Wet Well Volume
1.Wet well volume for a submersible pump station is the volume contained abovethe top of the motor, or as specified by the pump manufacturer, to the bottom ofthe influent pipe. TCEQ Rule 6217.60(b)(4) (d) A gravity pipe discharging to awet well must be located so that the invert elevation is above the liquid level of a
pump's "on" setting.
2. Wet well volume for all other non-submersible pump stations is the volumecontained in an area from a minimum of two (2) feet above or distance at which
vortexing does not occur above the top of the intake of the pump.
3. High level alarm elevation shall be a minimum of 48 inches below the top of thewet well or 48 inches below the flow line elevation of the lowest influent pipe,whichever elevation is lower. Wet well volume shall be calculated by the
following method:
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T= v + JD-Q Q
Where:
T = Total time between successive pumpstarts in minutes (operating cycle)D = Rated pump capacity in GPMV = Storage volume between lead pump onand pump off elevations in gallonsQ = Inflow to wet well in GPMThe operation cycle 'T’ shall not be lessthan 10 minutes for Average Flow and notmore than 60 minutes for Minimum Flowconditions.
4. Per TCEQ Rules, 30 TAC S 217.63:
(g) Systems for preventing the discharge of wastewater must operate for a
duration at least equal to the longest power outage on record for the past 60months, or at least 20 minutes, whichever is longer. The design must be basedon peak flows, inflow, and infiltration. If the longest power outage on record for
the past 60 consecutive months is greater than 48 hours and generators will beused to provide backup power, then the owner must have a contract in place thatguarantees fuel supply during an emergency. The owner must also havesufficient storage capacity at the wastewater treatment facility for the fuel for theduration of the emergency.
(h) For calculation purposes, the owner must assume that the lift station wet wellis full to the pump activation level when the power outage period begins.
D.Force Main Capacity
Force main capacity shall be sized to meet the capacity of the entire sewer basin.The force main may be designed to handle a portion of the basin with approval fromthe Director of Water Utilities. The minimum force main size shall be four (4) inchesin diameter, except for Grinder Pump lift stations. The minimum recommendedvelocity is 3 feet per second (3 fps), and the velocity shall not be less than 2 feet per
second (2 fps) when only the smallest pump is in operation.
4.21.4 PumpsAcceptable pumps are listed in the City of Denton Specification 33 25 02 SewagePumps. Substitutions or deviations from the list of acceptable pumps requires theapproval of the Director of Water Utilities.
4.21.5 MechanicalA. Force Main
1. Force main pipe material shall be in accordance with Table 4.9-1. Force mains
smaller than 6-inches may be approved with proper design justification, by theDirector of Water Utilities
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2.All fittings shall be ductile iron meeting AWWA C-110 or C-153. Interior of the
pipe and fittings shall be lined with American Polybond Plus, which consists of aprimer layer of 5 mils thick fusion bonded epoxy and 55 mils thick of modifiedDuPont Fusabond Polyethylene, or approved equal. Exterior of pipe shall becoated in Protecto 401 Ceramic Epoxy lining, or approved equal.
3.Force mains shall be laid to City of Denton Standard Specifications.
4. Plans shall include plan and profile for the force main, including valves every2000 feet per 30 TAC 217.67.
a.
b.
C.
Valves will be resilient wedge gate valves and conform to the Section 33 1420 Resilient Seated (Wedge) Gate Valves of the City of Denton StandardSpecificationsValves will be in a manhole and conform to Section 4.11 of this criteria
manual, Section 33 05 61 Cast-In-Place Concrete Manholes of the CityStandard SpecificationsThe force main shall have an isolation valve immediately downstream of theflow meter vault.
All force main contractors shall
Furnish and install tracer wire shall be furnished and installed in accordance
with City of Denton Standard Specification 33 05 97 Utility Markers/Locators,and
Furnish and install non-metallic pipe detection tape per TCEQ requirements.The tape shallBe laid in the same trench as a force main pipe,
Be located above and parallel to the force main, andBear the label ’'PRESSURIZED WASTEWATER" continuously repeatedin at least 1.5 inch tall letters.
b
1
11
111
a.
B. Lift Station Interior Piping
1.Piping inside the lift station shall be ductile iron meeting AWWA C-150 and C-151. All fittings shall be ductile iron meeting AWWA C-110 or C-150. Interior of
the pipe and fittings shall be lined with American Polybond Plus, which consistsof a primer layer of 5 mils thick fusion bonded epoxy and 55 mils thick ofmodified DuPont Fusabond Polyethylene, or approved equal.
2. All nut and bolt assemblies inside the wet well shall be ASTM 316 stainless
steel, unless otherwise allowed.
C. Isolation Valves
1. Each pump shall have one isolation valve downstream of the pump.
2. Isolation valves shall be resilient seat gate valves or plug valves meeting theCity of Denton Standard Construction Specification.
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3. Isolation valves shall be located in the building for self-priming stations, and in a
separate vault for submersible stations, and not inside the wet well.
D. Check Valves
1. Check valves shall be controlled closing swing check valves with a lever arm ora ball check. There must be at least 15 feet of vertical head downstream in orderto use a ball check valve.
2. A check valve shall be located upstream of the isolation valve.
3. If the station is submersible, then a check valve shall be located with theisolation valve in a separate vault. For self-priming stations, a check valve shallbe located in the building. Under no circumstance shall the check valve beallowed in the wet well.
4. All nuts and bolts shall be stainless steel.
E. Air Release/Vacuum Valves
1. Air release valves of a type suitable for wastewater service shall be installedalong the force main where the force main would be prone to trapped air.
2. The type of valve shall be air release or a combination of air release andvacuum breaker (see Drawing S803 on Sheet 6 of the City Standard Details).The design engineer shall determine the type and location, subject to approvalof the Director of Wastewater Utilities.
3. Calculations for valve type and valve sizing shall be provided to the City.4. Locations of the air release/vacuum valves shall be shown on the plan andprofile sheets for the force main.
5. Isolation valves for 3 inches and smaller air release valves shall be all bronze or
brass. Isolation valves 4 inches and larger shall meet City of Denton Standard
Construction Specification for resilient seat gate valve. The first fitting placedinto the force main shall be a brass corporate valve (male corporate fitting).
6. Air release valves shall be fitted with blow off valves, quick disconnect coupling
and hose to permit back flushing after installation without dismantling the valve.
7.Air release valves must be located in a vault as shown in Standard Details.
F. Generators
On-site generators shall be installed to serve as the source of back-up power for liftstations.
1. Generator shall be mounted on a concrete foundation designed to handle theweight of the generator
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4.21.6 Electrical, Instrumentation and Supervisory Control and Data Acquisition(SCADA) RequirementsThe City of Denton Water Reclamation department performs the build and install ofSCADA and telemetry packages. Developers should request the packet and COD will
provide a bill of materials for this service.
4.22 Low Pressure Collection Systems
Low pressure collection systems may be allowed with specific approval by the Directorof Water Utilities.
4.23 On-Site Sewage Facilities
4.23.1 General
Planning, design and operation of on-site sewage facilities within the City of Denton
must comply with the current Texas Administrative Code (TAC) Title 30, Part 1 TCEQRules, Ch. 285 for On-Site Sewage Facilities, as amended by the City of Denton. The
property owner proposing to use an on-site sewage facility shall comply with the criterialisted in this Section, and Sections 7.6.16 of the City of Denton Development Code.
4.23.2 Permits RequiredAny owner of a residential, commercial or institutional building who utilizes an on-sitesewage facility is required to secure a permit from the City of Denton to construct, alter,repair or extend an on-site sewage facility regardless of the size of the lot or tract ofland. Contact the Environmental Services Division at the Pecan Creek Water
Reclamation Plant for details on permit fees and maintenance requirements.
4.23.3 Site Evaluations
A professional engineer or a professional sanitarian, licensed by the State of Texas,must perform site evaluations.
4.23.4 Planning RequirementsA professional engineer or a professional sanitarian, licensed by the State of Texas,must prepare on-site sewage facility plans.
4.23.5 On-Site Sewage Facility Land Use Requirements
Lots or tracts of land where an on-site sewage facility is proposed must have thefollowing minimum area size.
• A minimum of 1 acre when a public water system serves the tract or lot.
• A minimum of 2 acres when a private water well is located on the tract or lot.
4.24 Grease Trap / Grit Traps
4.24.1 General
Planning, design, and operation of grease traps within the City of Denton must complywith the most current City of Denton Plumbing Code, Chapter 28; Article VII; Section 26-56 as amended. The property owner proposing to use and operate a grease trap shall
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comply with the criteria listed in this Section and abide by required responsibilitiesoutlined in City of Denton Code of Ordinances Chapter 26; Article XII – Liquid Waste.
4.24.2 Device RequiredAny user of the POTW, as defined by Section 26-153, and meeting the definition of “foodservice facilities” or “facilities which perform washing, cleaning, or servicing ofautomobiles, trucks, buses or similar equipment,” shall be required to install a grease
trap or grit trap in accordance with locally adopted plumbing codes as amended. Food
service establishments shall not share grease interceptors unless specifically authorizedby the Director of Water Utilities.
4.24.3 Sample Port RequiredAny pretreatment device must have a sample port allowing for the instantaneous grabsampling of the effluent of the device. The sample port must be solely representative ofthe process wastewater and sanitary tie-ins must be done down-stream of the sampling
port. The proposed sampling port must allow for a wide-mouthed 250 ml amber glass
bottle to be submerged / partially submerged into the effluent.
4.24.4 Review Required
Plumbing plans for new facilities must be prepared by a licensed plumber or a licensedprofessional engineer and submitted as a part of the development process. These plansmust show the fixtures draining into the pretreatment device. Plans must also include theflow-through rating of the pretreatment device as well as the grease or solids retention
capacity. Plans must also show the location of the down-stream sampling port.
4.24.5 Sizing Requirements
A. Definitions
1. Heavy Food Preparation: shall mean any area in which foods are preparedutilizing a grill, griddle, deep-fat fryer, commercial type ovens, and/or any similarfood preparation equipment; or any area subject to flooding type of wet cleaningprocedures due to the cutting or processing of meat, poultry, fish or pork; or any
facility subject to rinsing preparation equipment that is exposed to dairy products.Heavy food preparation includes but is not limited to: cafeterias, coffee shops,fast food restaurants, full service restaurants; pizza preparation, donut
preparation, and meat and fish markets, etc.
2. Light Food Preparation: shall mean any area in which foods are prepared
exclusive of the use of fryers, grills or similar equipment. Light food preparation is
usually limited to the preparation of hot dogs, sandwiches, salads or other similarfoods and fountain-type cold drinks. Light food preparation includes, but is notlimited to, sandwich shops, limited menu concession stands, etc.
3. No Food Preparation: shall mean any area in which foods are provided pre-
wrapped, from an approved source, with microwave oven type heating being themaximum handling involved. No food preparation is limited to pre-packagedsandwiches or similar foods, candies and containerized beverages.
B. Sizing Requirements
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Classification
Heavy Food Preparation
'Seating Capacjty >50
gravity750-gallongrease interceDtor
250-gallon gravitygrease interceptor
*Seating Capacjty <50
250-gallon greaseinterceDtor20flow-throughgpm40-poundratingor
retention capacit
Light Food Preparation
No Food Preparation No interceptor required
Or the rninirnum size established by the currently adopted International PlumbingCode; whichever is more stringent.
*Seating Capacity is measured using locally adopted Maximum Floor AreaAllowances per Occupant, found in the currently adopted version of the
International Building Code.
4.24.6 Inspection RequiredNew installations or existing pretreatment devices must be inspected by the City of
Denton Pretreatment Program prior to the issuance of a Certificate of Occupancy fornew businesses.
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Section 5 – Construction Plans
5. i General
Before any public works construction relative to a development may begin, City staff willverify the construction plans have been approved. Construction may not begin until theconstruction plans have been approved, all materials used for public improvements have
been submitted and approved, all fees (including review and inspection fees) have beenpaid, all necessary agreements and bonds have been provided, and a Pre-ConstructionConference has been held by the City.
5-2 Responsibility
The sealing engineer is responsible for the accuracy, completeness, and conformance ofthe submitted plans to City standards. The purpose of the City review is to ensureconformance to City policies and standards. The City review is limited to facts aspresented on the plans submitted. The City has no project engineering design or qualitycontrol review responsibility. The engineer certifying the plans is responsible for the
accuracy and completeness of the plan documents. The City reserves the right torequire plan corrections to fit actual field conditions or meet City standards requirements,which are found to be contrary to or omitted from the plans.
5.3 Format
Construction plans shall be digitally drawn on 24 in. by 36 in. size sheets; with borders of22 in. x 34 in. so half-size reproduced plans will be to half-scale fitting 11 in. x 17 in.sheets. Each sheet shall be legible when reduced to half-size.
5-4 Plan Requirements
Construction Plans must contain, as a minimum, information listed in the following
sections before they can be approved:
5.4.1 General
North arrow, scale, date and mean sea level elevations of all improvements, based onNorth America Vertical Datum 1988 (NAVD 88). Only NAVD 88 shall be used for planelevations; no assumed or NGVD 29 elevations. Plans shall be drawn with a horizontal
scale of one (1) inch equals forty (40) feet as a minimum, and appropriate correspondingvertical scale. The plans shall provide a reference to the elevation benchmark or
monument used in the development of the plans. Show all crossings of existing andproposed underground utilities. Plans shall account for future changes in topography.The construction plans shall be signed and sealed by a professional engineer, licensed
by the State of Texas, prior to bidding the project for construction.
5.4.2 Water SystemsPlan sheets must show the horizontal alignment of the proposed water system withinstreet rights-of-way and easements, with horizontal control points for location of therights-of-way and easements and for location of the water system within the rights-of-
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way and easements. Sizing of pipe, valves, fittings and appurtenances must be shownon the plan view. All valves, fittings, fire hydrants, and other appurtenances must be
stationed and given GPS coordinates based on the City of Denton’s grid coordinate
system. Profile views of water mains 12 inches or larger must be provided showingproposed grade, pipe material, casing pipe size and thickness (if any), and the location,
elevation and size of any underground conduit or facility to be crossed. Approvedvariances (if any) from City Standard Details must be provided. Show all service lines upto and including the meter can/vault. Service lines do not need to be stationed or have
GPS coordinates. Adequate detail of other planned and existing improvements shall beshown to indicate planned crossings of utilities, storm drains, and stormwater facilitiesand potential conflict points.
5.4.3 Sanitary Sewer Systems
Plan sheets must show the horizontal alignment of the proposed sanitary sewer systemwithin street rights-of-way and easements, with horizontal control points for location ofthe rights-of-way and easements and for location of the sanitary sewer system within the
rights-of-way and easements. Sizing of pipe, manholes, fittings and appurtenances mustbe shown on the plan view. Manhole rim elevations, and pipe “in” and “out” elevationsmust be shown. All manholes, fittings, and other appurtenances must be stationed and
given GPS coordinates based on the City of Denton’s grid coordinate system. Everysanitary sewer line shall be profiled. Profile views shall show proposed grade, pipe
material, casing pipe size and thickness (if any), manhole information, and the location,elevation and size of any underground conduit or facility to be crossed. Approvedvariances (if any) from City Standard Details must be provided. The plan view shallinclude arrows indicating direction of flow in pipe. Show all service lines to and includingthe public cleanout. Service lines do not need to be stationed or have GPS coordinates.Adequate detail of other planned and existing improvements shall be shown to indicate
planned crossings of utilities, storm drains, and stormwater facilities and potential conflictpoints
5.4.4 Grading
For situations involving proposed grading over existing water or sanitary sewer systems,provide a grading plan and profile showing the existing and proposed topography in two-
foot contours. The grading plan shall consist of contours and spot elevations with waterdirectional arrows to define the flow patterns.
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