21-255921-2559
ORDINANCE NO.
AN ORDINANCE OF THE CITY OF DENTON, TEXAS AMENDING THE WATER AND
WASTEWATER CRITERIA MANUAL; AND PROVIDING FOR SEVERABILITY, A
SAVINGS CLAUSE AND AN EFFECTIVE DATE.
WHEREAS, pursuant to Ordinance No. DCA18-0009q, 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 1991 Code
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
accordance with State law; and
WHEREAS, the creation of specific design standards and methodologies (the
"Development Criteria Manual") are delegated to City professional staff 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 with
generally 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 2018; 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 are
consistent 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, 2022.
The motion to approve this ordinance was made by �C.SSey; S and
seconded by Sa (1 M&g L) C e , the ordinance was passed and approved by
the following vote -7 - C ]:
Aye Nay Abstain Absent
Gerard Hudspeth, Mayor: ✓
Vicki Byrd, District 1:
Brian Beck, District 2: ✓
Jesse Davis, District 3: ✓
Alison Maguire, District 4: ✓
Deb Armintor, At Large Place 5: ✓
Paul Meltzer, At Large Place 6: ✓
PASSED AND APPROVED this, the INS day of b , 2021.
GERARD HU15SPETH, MAYOR
Page 2
ATTEST:
ROSA RIOS, CITY SECRETARY
BY:Q/_d
APPROVED AS TO LEGAL FORM:
MACK REINWAND, CITY ATTORNEY
Hilary Negron
/ vt�, 2021.12.09 11:07:39
BY: -06'00'
Page 3
EXHIBIT A
Page 4
City of Denton
Water and Wastewater Criteria Manual
D NTON
ADOPTED BY COUNCIL ORD. NO. 2019-###
December 2021
Table of Contents
I1/a ;`,vva er Criteria Manual
TABLE OF CONTENTS
SECTION1 - INTRODUCTION.................................................................................................5
SECTION 2 - REMOVED
SECTION 3 -WATER DESIGN GUIDELINES.............................................................................................6
3.1
GENERAL...............................................................................................................................6
3.2
WATER MAIN SEPARATION FROM WASTEWATER MAINS...............................................6
3.3
SIZE OF WATER DISTRIBUTION MAINS...........................................................................6
3.3.1
Public Fire Hydrants..........................................................................................................8
3.3.2
Private Fire Mains.............................................................................................................8
3.3.3
Fire Flow Tests...............................................................................................8
3.4
DEPTH OF COVER FOR WATER MAINS...............................................................................9
3.5
PIPE AND FITTINGS...............................................................................................................9
3.6
METERS AND METER CANS /VAULTS ..............................................................................11
3.6.1
NUMBER OF METERS...............................................................................................................11
3.6.2
Sizing..............................................................................................................12
3.6.3
Location............................................................................................................19
3.6.4
Furnishing and Installing.......................................................................................19
3.6.5
Details...............................................................................................................19
3.7
WATER MAIN HORIZONTAL AND VERTICAL ALIGNMENT......................................19
3.8
HIGHWAY CROSSINGS...........................................................................................20
3.9
RAILROAD CROSSINGS...........................................................................................
20
3.10
CREEK CROSSINGS...............................................................................................20
3.11
TUNNELING, BORING .LACKING AND CASING................................................................20
3.12
ELEVATED CROSSINGS. ..........................................................................................
21
3.13
UNDERGROUND UTILITY CROSSINGS..........................................................................21
3.14
FENCE OR WALL CROSSINGS...................................................................................22
3.15
EXISTING WATER MAIN REPLACEMENT.......................................................................22
3.16
METHODS OF CONNECTION.....................................................................................23
3.16.1
Pressure Zones.............................................................................................23
3.16.2
Tapping Sleeve and Valve..............................................................................25
3.16.3
Type "D» Connection......................................................................................25
3.16.4
Cut -In Connection...........................................................................................................25
3.16.5
Main Extensions..............................................................................................................25
3.17
VALVES...................................................................................................................................25
3.17.1
Isolation Valves.................................................................................................25
3.17.1.1
Location........................................................................................................25
3.17.1.2
Specifications.................................................................................................26
3.17.1.3
Details..........................................................................................................27
3.17.2
Air Release Valves and Air/ Vacuum -Air Release Valves........................................27
3.17.3
Pressure Regulators........................................................................................27
3.18
DEAD-END MAINS.....................................................................................................................27
3.19
FIRE HYDRANT LOCATIONS AND COVERAGE..............................................................................27
3.20
REQUIREMENTS FOR ABANDONING WATER MAINS.....................................................................28
3.20.1
Replacement Mains........................................................................................................28
3.20.2
Extension Mains..............................................................................................................28
2
Table of Contents
Wafer and WastNviater Criteria Manual
3.20.3 Fire Hydrants...................................................................................................................28
3.21 Flushing and Disinfection..................................................................................28
SECTION 4 -WASTEWATER DESIGN GUIDELINES.................................................................30
4.1
GENERAL............................................................................................................................................30
4.2
ESTIMATED WASTEWATER FLOWS............................................................................................30
4.3
Separation Distances between WW Collection System Pipes and Manholes...................31
4.4
SIZE AND SLOPE OF SEWERS....................................................................................................32
4.4.1
High Velocity Protection..................................................................................................33
4.5
SEWER MAIN DEPTH................................................................................................................33
4.6
RECOMMENDED COVER............................................................................................................33
4.7
SEWER ALIGNMENT..................................................................................................................33
4.8
SEWER LATERALS....................................................................................................................34
4.9
GRAVITY AND FORCE MAIN SEWER PIPE MATERIAL...................................................................34
4.10
SEWER PIPE EMBEDMENT........................................................................................................35
4.11
MANHOLES..............................................................................................................................35
4.11.1
Manhole Locations..........................................................................................................36
4.12
HIGHWAY CROSSINGS..............................................................................................................36
4.13
RAILROAD CROSSINGS.............................................................................................................37
4.14
TUNNELING, BORING, .LACKING AND CASING...............................................................................37
4.15
UNDERGROUND UTILITY CROSSINGS........................................................................................38
4.16
Fence or Wall CROSSINGS......................................................................................................38
4.17
Creek Crossings......................................................................................................................38
4.18
SIPHONS..................................................................................................................................38
4.19
ABANDONMENT OF SEWER MAINS.............................................................................................38
4.20
ABANDONMENT OF MANHOLES..................................................................................................39
4.21
LIFT STATIONS.........................................................................................................................39
4.21.1
Preliminary Design Submittal..........................................................................................39
4.21.2
Site Layout......................................................................................................................40
4.21.3
Hydraulic Design.............................................................................................................42
4.21.4
Pumps.............................................................................................................................44
4.21.5
Mechanical......................................................................................................................44
4.21.6 Electrical, Instrumentation and Supervisory Control and Data Acquisition (SCADA)
Requirements..................................................................................................................45
4.22
LOW PRESSURE COLLECTION SYSTEMS....................................................................................45
4.23
ON-SITE SEWAGE FACILITIES...................................................................................................46
4.23.1
General.......................................................................................................46
4.23.2 Permits Required.............................................................................................................46
4.23.3 Site Evaluations...............................................................................................................46
4.23.4 Planning Requirements...................................................................................................46
4.23.5 On -Site Sewage Facility Land Use Requirements..........................................................46
SECTION5 - CONSTRUCTION PLANS...................................................................................47
5.1 GENERAL.................................................................................................................................47
5.2 RESPONSIBILITY.......................................................................................................................47
K
5.3
5.4
5.4.1
5.4.2
5.4.3
5.4.4
FORMAT ..............................
PLAN REQUIREMENTS ..........
General
Table of Contents
Water and Wastewater Criteria Manual
.47
.47
47
WaterSystems...............................................................................................47
Sanitary Sewer Systems................................................................................. 48
Grading........................................................................................................48
4
Section _r
Water and Wastewater Criteria Manual
Section 1 — Introduction
1.1 Purpose _ _..__._
The purpose of this Manual is to provide minimum guidelines for the design and
construction of water distribution and wastewater collection systems within the City of
Denton, Texas and its extra -territorial jurisdictions. The criteria established in this Manual
have been developed from a review of various applicable publications, North Central
Texas Council of Government (NCTCOG) Public Works Construction Standards (as
amended by the City of Denton), 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 Capital Projects
Engineering Division, consulting engineers employed by the City, and engineers of
subdivision and land development infrastructure projects proposed for construction and
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 and application of
water and wastewater engineering. Alternative designs may be submitted for
consideration but will require additional time to evaluate, and the Director of Water Utilities
must approve any deviations from criteria established in this Manual.
Along with this Manual, the Denton Development Code (DDC) should be consulted for
additional criteria. The criteria established in this Manual do not supersede the criteria
contained in the DDC. In the case of conflict among this Manual, NCTCOG Public Works
Construction Standards as amended by the City of Denton, City of Denton Standard
Details, or other cited regulations and standards, the more stringent requirement shall
apply.
Section 3
{Nater and Wastewater Criteria Manual
Section 3 — Water Design Guidelines
3.1 General
It is the responsibility of the design engineer to ensure the final design of a water main is
in conformance with the most recent versions of the following documents:
A. Texas Administrative Code (TAC) Title 30, Part 1, Texas Commission on
Environmental Quality (TCEQ) — Rules, Ch. 290, "Public Drinking Water"
B. Denton Development Code (DDC)
C. This Manual and the City's Standard Details
D. North Central Texas Council of Governments (NCTCOG) Standard Specifications for
Public Works Construction ("COG Specs."), as amended by the City of Denton
E. City of Denton Water Master Plan
F. Appendix B of the 2012 International Fire Code
G. American Water Works Association (AWWA) Standards
3.2Water 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 recently amended.
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 Master
Plan (Master Water Plan). All residential, commercial, industrial, and any other
development connecting to the City's water distribution system shall use the following
guidelines:
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's Master
Water Plan, for sizing the water lines.
• Average daily demand in gallons per capita per day = 170 GPCD
Maximum daily demand / Average daily demand = 2.0
Peak 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 supply
to furnish fire protection to all lots and conform to the City Master Water Plan. Every
new water system shall include two or more connections to the existing City water
system, when feasible, to ensure an adequate and reliable water supply in the event
of a water main break or routine system maintenance. The City may require two or
more meter connections, particularly for larger developments. Good engineering
judgement is required to ensure reliability is considered in design of all proposed water
systems.
A
Section 3
Water and Wastewater Criteria Manual
C. The City's standardized water service line sizes are:
Table 3.3-1
Service Size Meter Size
1 in. 1 5/8 in. x 3/4 in., full 3/4 in., and 1 in.
2 in.
1-1/2 in. and 2 in.
4 in.
3 in. and 4 in.
6 in.
6 in.
8 in.
8 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 connections
onto 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 that
shall be used for water main lines are 8", 12", 16", 20", 24", 30", 36" and 42". Pipe sizes
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 hydrant connections
and, with approval of the Director of Water Utilities, for short dead-end mains with a
limited number of service connections.
F. Every development shall provide adequate water capacity for fire protection purposes.
Fire flow capacity requirements are in addition to daily demand requirements. The
procedure for determining fire flow requirements for buildings or portions of buildings
shall be in accordance with version of the International Fire Code adopted in the City.
For any platted lot where the end use is not defined, the standards in Table 3.3-2 shall
apply.
G. If a development requires a dedicated fire line, the fire line connection shall have a
backflow prevention device placed in a vault at the right-of-way or easement line. If
the building is located within 50 feet of the right-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 or ROW line whichever applies.
7
Section 3
Water and Wastewater Catena Manual
Table 3.3-2
One and two family dwellings less
1,000
than 3,600 SF
Buildings other than one and two
1,500
family dwellings less than 3,600 SF
Medium -intensity commercial and
3,000
light industrial
High-intensity commercial and
4,000
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
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 of C =
100, except for fire flow demands within the subdivision internal
distribution system.
Special exceptions to the above standards may be made by the
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 of
Ordinances and Appendix B of the 2012 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 2012 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 MEP engineer, and
other engineers to determine available water system capacity at or near the point of
interest. If a fire flow test on the existing water system is necessary, contact the Water
Utilities Department directly.
Section ,3
Water and Wastewater Criteria Manua!
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
Table 3.4-2
Water Main under proposed or existing pavement
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 applicable to the
specific project. Pipe gasket material shall be that recommended by the manufacturer 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 horizontal
bends, shall have concrete thrust blocking. See Drawings W700, W701, W702A, W70213,
W702C, and W703 on Sheet 3 of the City Standard Details.
For all water line sizes, all fittings, including vertical and horizontal bends, shall have
restrained joints, designed independently of concrete thrust blocking. For water lines
greater than 12 inches in diameter additional restrained joints may need to be installed
beyond the fitting (i.e., may need to be installed on several pipe joints on each side of the
R
Section 3
Wafer and Wastewater Criteria &Ianual
fitting), depending on the required restrained length calculated. Restrained length
calculations shall be included in the lay schedule in the material submittal package and
shall 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
Pipe Size
Pipe Material
Ductile Iron
Polywrap
(Pipe &
(IN ADDITION TO AND
Embedment
Fittings
Fittings)
DESIGNED INDEPENDENTLY
OF THRUST BLOCKING)
PVC
Mechanical
8 -mil V -Bio
See drawings U201,
8 in. -12 in.
(AWWA C900, DR-
joint;
Enhanced
Wedge -action mechanical joint
U202, U203A, U203C
14)
Compact or
Polywrap
restraint glands, at fittings.
in City Standard Details
Full-Bod
(fitting ons
Ductile Iron, AMA
C151, Special
8 -mil V -Bio
Wedge -action mechanical joint
Thickness Class
Enhanced
restraint glands, at fittings.
52, push -on joints
Mechanical
Polywrap
Boltless Restrained connections
(Example: American Flex -Ring
See drawings U201,
(where
joint;
(inner layer),
joint), at several pipe joints either
U202, U203A, U203C
unrestrained;
Full -Body
plus 4 -mil
side of each fitting, depending on
in City Standard Details
16 in. - 20 in.
example:
American Flex -Ring
cross-linked
(outer layer)
the required restrained length
joint
calculated.
Reinforced
Bonded joint
Concrete Steel
N/A
and Cathodic
Protection
Full Circle Welded Joints required
Contact Water Utilities
Cylinder, AWWA
(CP) System
for thrust restraint
Dept.
C303 Bar Wrapped
required
Ductile Iron, AWWA
C151, Special
8 -mil V -Bio
Wedge -action mechanical joint
Thickness Class
Enhanced
restraint glands, at fittings.
52, push -on joints
Mechanical
Polywrap
Boltless Restrained connections
( where
joint;
(inner layer),
(Example: American Flex -Ring
Crushed Stone
unrestrained;
Full -Body
plus 4 -mil
joint), at several pipe joints either
example:
cross-linked
side of each fitting, depending on
24 in.
Flex -Ring
American Flex -Rin
(outer layer)
the required restrained length
joint
calculated.
Reinforced
Bonded joint
Concrete Steel
N/A
and Cathodic
Protection
Full Circle Welded Joints required
Contact Water Utilities
Cylinder, AWWA
(CP) System
for thrust restraint.
Dept.
C303 Bar Wrapped
required
Ductile Iron,
8 -mil V -Bio
Wedge -action mechanical joint
Pressure Class
Enhanced
restraint glands, at fittings.
350; push -on joints
Mechanical
Polywrap
Boltless Restrained connections
(where
joint;
(inner layer),
(Example: American Flex -Ring
Crushed Stone
unrestrained;
Full-Bodyjoint),
plus
at several pipe joints either
30 in. and
example:
inked
cross-linked
side of each fitting, depending on
larger
American Flex -Ring
joint)
(outer layer)
the required restrained length
calculated.
Reinforced
Bonded joint
Concrete Steel
N/A
and Cathodic
Protection
Full Circle Welded Joints required
Contact Water Utilities
Cylinder, AWWA
(CP) System
for thrust restraint.
Dept.
C303 Bar Wrapped
required
lv
Section 3
Wafer and WaVewater Criteria Manual
3.6 Meters and Meter Cansll/aults
The City allows the following water meters, depending on the volume and nature of the
customer flow demands:
Table 3.6-1
Meter Size
Type Manufacturer
5/8" x 3/4"
Positive Displacement Neptune/Badger
3/4" x 3/4"
Positive Displacement
Neptune/Badger
1"
Positive Displacement
Neptune/Badger
1-1/2"
Positive Displacement
Neptune/Badger
2"
Positive Displacement
Compound
Neptune/Badger
Neptune/Badger
3" Tru/Flo
4" Tru/Flo
Com ound
Compound
Neptune Bad er
Neptune/Badger
6" Tru/Flo a
6" Protectus III Fire Service
(Shall be used for
combination of domestic and
fire service
Compound
Neptune/Badger
8" Protectus III Fire Service
(Shall be used for
combination of domestic and
fire service)
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 on
Single 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
The standard policy is that only one meter for domestic use will be furnished to each lot.
Submetering by the property owner shall be done at the owner's expense with privately
purchased and maintained meters. Exceptions to that policy are:
1) Commercial, industrial or institutional sites shall have a separate irrigation meter from
the domestic meter.
2) Multi -family developments with greater than 200 units shall be required to have two
meters for redundancy and reliability of water service where each meter is located on
a different water main or separated by an inline valve.
3) Multi -building sites where the configuration or size of the site makes a single meter
location impractical or infeasible.
4) Duplex, Triplex or Quadplex buildings may have a separately furnished meter for each
unit. A single service line tap off of the main shall be made for these building types
with a branch service line for each meter.
11
Section 3
Water and Wastewater Criteria Manual
3.6.2 Sizing
In commercial and industrial projects, the design engineer shall consult with the owner or
the Mechanical, Electrical and Plumbing (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 Table
E201.1, "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 Building Permit
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 Plumbing Fixture 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 shall submit a tabulation
of water supply fixture units (w.s.f.u.); a sample tabulation is provided herein 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 City Code,
water and wastewater Impact Fees are based on water meter size, with the following
exceptions:
A. For multifamily developments of 8 or more units, Impact Fees are based on bedroom
count.
B. For fire -rated master meters, Impact Fees are based on the equivalent meter size the
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 assisted
living facilities the Water Department will need to be consulted as to the appropriate
methodology for sizing the meter.
Refer to Table 3.6.2-4, "Land Use and Service Unit/SFE Equivalencies." Impact Fees are
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
Waterand WastewaterCntaria Manual
TABLE 3.6.2-1
2018 International Plumbing Code -TABLE E201.1
MINIMUM SIZE OF WATER METERS, MAINS AND DISTRIBUTION PIPING
BASED ON WATER SUPPLY FIXTURE UNIT VALUES (w.s.f.u.)
Note a: Minimum size for building supply is 3/4 -inch pipe.
13
MAXIMUM
60 80
2 1.5
DEVELOPMENT
100
1.5
150
1
200
1
250 300 400
0.5 0.5 0
500
0
METER ■
DISTRIBUTION
SERVICE PIPE
PIPE (inches)
Pressure Range 30 to 39 psi
3/4 1/2a
40
2.5
3/4
3/4
9.5
7.5
6
5.5
4
3.5
3
2.5
2
1.5
3/4
1
32
25
20
16.5
11
9
7.8
6.5
5.5
4.5
1
1
32
32
27
21
13.5
10
8
7
5.5
5
3/4
1-1/4
32
32
32
32
30
24
20
17
13
10.5
1
1-1/4
80
80
70
61
45
34
27
22
16
12
1-1/2
1-1/4
80
80
80
75
54
40
31
25
17.5
13
1
1-1/2
87
87
87
87
84
73
64
56
45
36
1-1/2
1-1/2
151
151
151
151
117
92
79
69
54
43
2
1-1/2
151
151
151
151
128
99
83
72
56
45
1
2
87
87
87
87
87
87
87
87
87
86
1-1/2
2
275
275
275
275
258
223
196
174
144
122
2
2
365
365
365
365
318
266
229
201
160
134
2
2-1/2
533
533
533
533
533
495
448
409
353
311
Note a: Minimum size for building supply is 3/4 -inch pipe.
13
Section 3
Water and Wastewater Oritera Manual
TABLE 3.6.2-1 (continued)
3/4
1/2a
3
2.5
2
1.5
1.5
1
1
0.5
0.5
0.5
3/4
3/4
9.5
9.5
8.5
7
5.5
4.5
3.5
3
2.5
2
3/4
1
32
32
32
26
18
13.5
10.5
9
7.5
6
1
1
32
32
32
32
21
15
11.5
9.5
7.5
6.5
3/4
1-1/4
32
32
32
32
32
32
32
27
21
16.5
1
1-1/4
80
80
80
80
65
52
42
35
26
20
1-1/2
1-1/4
80
80
80
80
75
59
48
39
28
21
1
1-1/2
87
87
87
87
87
87
87
78
65
55
1-1/2
1-1/2
151
151
151
151
151
130
109
93
75
63
2
1-1/2
151
151
151
151
151
139
115
98
77
64
1
2
87
87
87
87
87
87
87
87
87
87
1-1/2
2
275
275
275
275
275
275
264
238
198
169
2
2
365
365
365
365
365
349
304
270
220
185
2
2-1/2
533
533
533
533
533
533
533
528
456
403
Note a: Minimum size for building supply is 3/4 -inch pipe.
14
Section 3
Waterand Wastadrater Criteria Manual
TABLE 3.6.2-1 (continued)
Note a: Minimum size for building supply is 3/4 -inch pipe.
15
MAXIMUM DEVELOPMENT
.1 :1 100 150
3 2.5 2 1.5
200 250 300 400
1 1 1 0.5
500
0.5
METER AND
SERVICE
PIPE (inches)
Pressure ••
3/4
DISTRIBUTION
PIPE
(inches)
50 to .1 psi
1/2a
40
3
3/4
3/4
9.5
9.5
9.5
8.5
6.5
5
4.5
4
3
2.5
3/4
1
32
32
32
32
25
18.5
14.5
12
9.5
8
1
1
32
32
32
32
30
22
16.5
13
10
8
3/4
1-1/4
32
32
32
32
32
32
32
32
29
24
1
1-1/4
80
80
80
80
80
68
57
48
35
28
1-1/2
1-1/4
80
80
80
80
80
75
63
53
39
29
1
1-1/2
87
87
87
87
87
87
87
87
82
70
1-1/2
1-1/2
151
151
151
151
151
151
139
120
94
79
2
1-1/2
151
151
151
151
151
151
146
126
97
81
1
2
87
87
87
87
87
87
87
87
87
87
1-1/2
2
275
275
275
275
275
275
275
275
247
213
2
2
365
365
365
365
365
365
365
329
272
232
2
2-1/2
533
533
533
533
533
533
533
533
533
486
Note a: Minimum size for building supply is 3/4 -inch pipe.
15
Section 3
Water and Wastewater Criteria Manual
TABLE 3.6.2-1 (continued)
3/4
1/2a
3
3
3
2.5
2
1.5
1.5
1
1
0.5
3/4
3/4
9.5
9.5
9.5
9.5
7.5
6
5
4.5
3.5
3
3/4
1
32
32
32
32
32
24
19.5
15.5
11.5
9.5
1
1
32
32
32
32
32
28
28
17
12
9.5
3/4
1-1/4
32
32
32
32
32
32
32
32
32
30
1
1-1/4
80
80
80
80
80
80
69
60
46
36
1-1/2
1-1/4
80
80
80
80
80
80
76
65
50
38
1
1-1/2
87
87
87
87
87
87
87
87
87
84
1-1/2
1-1/2
151
151
151
151
151
151
151
144
114
94
2
1-1/2
151
151
151
151
151
151
151
151
118
97
1
2
87
87
87
87
87
87
87
87
87
87
1-1/2
2
275
275
275
275
275
275
275
275
275
252
2
2
365
368
368
368
368
368
368
368
318
273
2
2-1/2
533
533
533
533
533
533
533
533
533
533
Note a: Minimum size for building supply is 3/4 -inch pipe.
16
TABLE 3.6.2-2
2018 International Residential Code
Section 3
Water and Wastewater Criteria Mantra!
P2903.6 Determining Water -Supply Fixture Units
Supply loads in the building water -distribution system shall be determined by total load on the pipe being sized, in
terms of water -supply fixture units (w.s.f.u.), as shown in Table P2903.6, and gallon per minute (gpm) flow rates (see
Table P2903.6(1)]. For fixtures not listed, choose a w.s.f.u. value of a fixture with similar flow characteristics.
TABLE P2903.6
WATER -SUPPLY FIXTURE -UNIT VALUES FOR VARIOUS PLUMBING FIXTURES AND FIXTURE GROUPS
TYPE OF FIXTURES OR GROUP OF FIXTURES
WATER -SUPPLY FIXTURE -UNIT VALUE
(w.s.f.u.)
Hot
Cold
Combined
Bathtub (with/without overhead shower head)
1.0
1.0
1.4
Clothes washer
1.0
1.0
1.4
Dishwasher
1.4
-
1.4
Full -bath group with bathtub (with/without shower head) or
shower stall
1.5
2.7
3.6
Half -bath group (water closet and lavatory)
0.5
2.5
2.6
Hose bibb (sillcock)a
-
2.5
2.5
Kitchen group (dishwasher and sink with/without garbage
grinder)
1.9
1.0
2.5
Kitchen sink
1.0
1.0
1.4
Laundry group (clothes washer standpipe and laundry tub)
1.8
1.8
2.5
Laundry tub
1.0
1.0
1.4
Lavatory
0.5
0.5
0.7
Shower stall
1.0
1.0
1.4
Water closet (tank type)
-
2.2
2.2
For SI: 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 lawn
sprinkler device. If a hose bibb/sill cock will be required to furnish a greater flow, the equivalent
fixture -unit value may be obtained from this table or Table P2903.6(1).
17
Section .3
Wafer and Wasteviater Criteria Manua/
Table 3.6.2-3
QuantitySAMPLE
W.S.F.U. TABULATION
Load Values, in Total
. .
Units (Each)
Total Fixture
9
Water Closet (Public; Flush Valve)
10.0
90
3
Water Closet (Public; Flush Tank)
5.0
15
5
Urinal (Public; 3/4 -inch Flush Valve)
5.0
25
10
Lavatory (Public)
2.0
20
2
Kitchen Sink (Hotel, Restaurant)
4.0
8
1
Service Sink
3.0
3
1
Shower Head (Private)
1.4
1.4
Total
162.4
Table 3.6.2-4
Positive Displacement
Residential - Single Family
(Building less than 1,300 sq. ft./
5/8" X 3/4" lot size less than 6,000 sq. ft.)
0.5
Positive Displacement
5/8" X 3/4"
Residential - Single Family
1.0
Positive Displacement
3/4" X 3/4"
Residential / Commercial
1.5
Positive Displacement
1"
Residential / Commercial
2.5
Positive Displacement
1-1/2"
Commercial
5.0
Positive Displacement
2"
Commercial
8.0
Compound
3"
1 Commercial / Industrial
22.5
Compound
4"
1 Commercial / Industrial
50.0
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 determined
by multiplying the total number of bedrooms in the multi -family apartment project by 0.26 Single Family
Equivalents SFEs).
Section
water anti vlaste ster Criteria Manttai
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 Installing
All 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 associated
vaults shall be furnished and installed by Contractor at their expense and inspected by
Public 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 Drawings
W501 A, W501 B, W501 C, and W502 on Sheet 2 of the City Standard Details.
Details of the meter vault assemblies for meter sizes 3" and larger are shown in Drawings
W100, W101, W102, and W103 on Sheet 1 of the City Standard Details.
3.7Water Main Horizontal and Vertical Alignment
The following guidelines should be followed by the design engineer in placement of water
lines:
A. In existing streets, water lines shall be placed in the pavement 2 feet inside of the curb
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 Drawing U101 on Sheet 7 of 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 be restricted
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 joint
deflection; no bending of pipe is allowed.
D. Vertical bends shall be no greater than 45 degrees.
E. Except for pipe crossings, no other utility shall be installed over, under or within 5 ft.
horizontally of a water line.
19
Section 3
Water and Wastewater Criteria Manual
F. Provide at least 2 feet of vertical separation between a water line and any utility or
storm drain crossing it.
3.8 Highway Crossings
Crossings of State or County controlled roads shall require the review and approval of the
appropriate regulatory agency. Crossings shall meet the requirements made by the
controlling agency and by City of Denton Standards. In the event of different requirement
levels 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 the
appropriate railroad company and regulatory agency and determine if there are any
special requirements. In the event City of Denton Design Criteria are more stringent than
those of the Railroad Company or regulatory agency, the City's standards shall apply. See
Section 6.4.A for processing of railroad permits.
3.10Creek Crossings
Where water mains are laid under any flowing stream or semi-permanent body of water,
such as a marsh or pond, 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.
A primary consideration in the design of creek crossings is the prevention of soil erosion
in the areas of trench backfill. The design engineer shall determine the need and limits of
any special embedment and determine and specify the limits for specialized backfills.
3.11 Tunneling, Boring, Jacking and Casing
Tunneling, boring, jacking and Casing are methods used for water line placement under
restrictive conditions when open -cut construction is not allowed. Only straight pipe
alignments for both horizontal and vertical alignment are allowed.
Design engineers should consider the location, size and depth of boring and receiving pits
when choosing the beginning and ending stations for boring. A typical bore pit is between
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 the narrowest width
being approximately 15 ft. The preferred location for the bore pit is the lower elevation
end of the bore; allowing any groundwater and/or boring slurry to drain from 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, shall
have an inside diameter (ID) large enough to accommodate a carrier pipe of at least two
20
Section 3
Water and Wastewater ;- In Varwal
(2) standard sizes above the pipe being installed and shall meet the minimum ID listed in
Table 3.11-1. The casing pipe wall thickness design shall be based on the requirements
of the agency whose facility is being crossed and shall conform to the minimum criteria
listed in Table 3.11-1. Casing pipe shall be provided with interior and exterior coal -tar
protective coating in accordance with AWWA C203. Field welds shall be coated with an
equivalent coating.
Table 3.11-1
Nominal Carrier Pipe Minimum
Size
8 in.
Casing Pipe Minimum
ID
12 in.
Casing Pipe
Wall Thickness
3/8 in.
12 in.
20 in.
1/2 in.
16 in.
24 in.
1/2 in.
20 in.
30 in.
1/2 in.
24 in.
36 in.
5/8 in.
30 in.
42 in.
5/8 in.
>30 in.
a
b
a. Consult with Water Utilities Department
b. Project specific design, sealed and signed by a Professional Engineer licensed
by the State of Texas
Carrier pipes may be PVC with external harness restrained joints (requires larger casing
than for pipe alone) or ductile iron with restrained joints. All carrier pipes shall be installed
in accordance with the pipe manufacturer's recommendations, properly restrained and
supported with approved spacers and casing end seals. Pipe joint restraint shall be
achieved using only City approved pipe manufacturer externally restrained joint systems.
Refer to Standard Detail U208A and the current City approved Materials Submittal List.
3.12 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 crossings
shall be tailored to the specific project characteristics.
3.13 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 may be
necessary for the protection of the water main. Table 3.13-1 gives a breakdown of the
provisions required for different crossing situations.
21
Section 3
Water anti Wastewater Criteria Mantra;
Table 3.13-1
Utility Crossing Requirements
Crossing
Utility Line Size (in)
Separation (ft)
Special Requirement
Under
less than 24
>= 2
None
Under
less than 24
< 2
Concrete encasement
Under
24 to 42
>= 2
None
Under
24 to 42
< 2
Cased in steel pipe
Under
Greater than 42
>= 2
Cased in PVC pipe
Under
Greater than 42
< 2
Cased in steel pipe
Under
10 feet or greater
Any
Cased in steel pipe
Over
less than 24
>= 2
None
Over
less than 24
< 2
Concrete encasement
Over
24 or greater
>= 2
None
Over
24 or greater
< 2
Cased in steel pipe
Encasement shall be extended a minimum of 3 feet beyond the edge of the utility or facility
to be crossed. Water mains that cross utility lines in private easements must adhere to the
requirements of the easement owner as well as those listed above.
3.14 Fence or Wall Crossings
Where water mains cross under a fence, wall or some other border structure, special
provisions may be required for the protection and maintenance of the water main. Water
mains crossing under privacy fencing (wood or chain-link) shall not require any special
protection. Water mains crossing under a screening or border wall will require steel casing
pipe to allow for removal of the pipe from either side of the wall. A water main crossing
under a retaining wall or some other structure serving a soil retention purpose shall be
encased in steel encasement that extends a minimum of 5 feet beyond the footing for the
wall or structure.
3.15 Existing Water Main Replacement
Whenever an existing main is to be replaced by a new main use the following guidelines
for 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 under
existing pavement, not behind the curb in the parkway area.
3) The new line should be designed to utilize the existing metering locations where
possible.
The size of the new line should match the size of the existing line. If the existing line is a
non-standard size (i.e., 6" or 10") than the new line should be sized for the next larger
standard size. The design engineer shall perform field investigations to determine
pavement condition over the existing main. The pavement may have been patched due
to breaks in the existing main over the years. Based on field investigations, the design
engineer shall include additional quantities for pavement replacement, if necessary.
22
3.16 Methods of Connection
3.16.1 Pressure Zones
The City of Denton's Water Distribution System
zones to ensure even water pressure gradients.
between a proposed main and any existing mail
and determine if the proposed water main cr(
pressure zones.
Section 3
Mater and Wastewater Crited a Manual
is divided into several water pressure
Prior to the design of connection points
i, the design engineer shall investigate
)sses the boundary between different
Even though physical connections of water pipes exist between pressure zones, they are
designed with valves which are closed at the boundary points so that each pressure zone
is isolated. Proposed mains that approach pressure zone boundaries shall be designed
to loop within their designated pressure zones and with no or minimum lengths of dead-
end mains.
Connections between pressure zones must be approved by the City of Denton, and may
require pressure reducing valve stations. The design engineer can determine the pressure
zone boundaries by consulting the record drawing water maps which show the designated
closed valves between pressure zones and by contacting the Capital Projects Engineering
Division. See Figure 3.16.1-1 for a Pressure Zone Map.
23
Section 3
Water and Wasteviater Criteria Manual
FIGURE &I
CITY OFDRNTON
WATUSYSTEM
17HCIFOSED PRESSUO- PLAINES
FRE"r. ------
DIENTON
Fill
1' 4
f
4�f I
17,
7.1. ......
57
elm
k
SCALE 114 FEET
Figure 3.16.1-1 Pressure Zone Map
24
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 to
existing mains to avoid interruption of water services. See Figure 3.1 in Drawing PIAZ13
on Sheet 2 of 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 Director
of Water Utilities, and at least one standard pipe size smaller than the pipe being
tapped. See Figure 3.2 in Drawing PIAZ13 on Sheet 2 of the City Standard Details.
(Example: 16" X 12", 16" X 8" and 16" X 6" taps are allowed).
3.16.3 Type "D" Connection
When two mains 12" and larger are designed such that they cross each other, they should
be connected by means of a Type "D" connection, instead of the installation of a cross.
See Figure 3.3 in Drawing PIAZ13 on Sheet 2 of the City Standard Details.
3.16.4 Cut -In Connection
On occasions when connecting to an existing main, it may be desirable to have an
additional 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 on Sheet 2 of the City Standard Details.
3.16.5 Main Extensions
It is recommended and good practice, though not required, that a new valve be installed
at the point of connection for water main extensions. This will facilitate the testing and
chlorination of the new main prior to its placement into service. See Figure 3.5 in Drawing
PIAZ14 on Sheet 2 of the City Standard Details.
3.17 Valves
3.17.1 Isolation Valves
3.17.1.1 Location
Isolation valves shall be provided to allow for the proper operation and maintenance of the
water distribution system, and to ensure water quality can be maintained to each individual
water customer connected to the system.
The location of valves needs to properly address the ability of the Department of Water
Utilities to remove a water line from service to perform necessary repairs, while minimizing
the interruption of service to the least number of customers and to fire protection. Isolation
of any given section of water line should generally be able to be accomplished by closure
of the least number of valves, as would generally be expected under good engineering
design practices and utility engineering standards. The Department of Water Utilities
reserves the right to require changes to proposed designs to satisfy these objectives.
The design engineer shall place valves on proposed water mains so they may be easily
located in the future by operations and maintenance crews.
25
Section 3
'Nater and 01astoowater 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 flanged to the branch of the
tee and the other a mechanical joint connection on one of the two runs of the tee. See
Figure 3.6 in Drawing PIAZ15 on Sheet 2 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 apart
than 1,000 feet. For city blocks that are longer than 1,000 feet between street
intersections, 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 required
to isolate a section of main. See Figure 3.7 in Drawing PIAZ15 on Sheet 2 of the City
Standard Details. For mains larger than 12" in diameter, valve spacing and placement
shall be subject to alternate criteria approved by the Director of Water Utilities.
D. All fire hydrant leads are to be designed with a valve that is flanged to the main line.
3.17.1.2 Specifications
Refer to Table 3.17.1.2-1.
Table 3.17.1.2-1
Isolation Valve Requirements
Size
4 in. -12 in.
16 in. - 20 in.
24 in.
30 in.
36 in. or larger
Gate Valve
Gate Valve
Gate Valve
Gate Valve (AWWA
(AWWA
(AWWA
(AWWA
Gate Valve
C515 resilient -seat) or
Type
C509
C515
C515
(AWWA C515
butterfly, to be
resilient -seat)
resilient -seat)
resilient -seat)
resilient seat)
determined by City on a
case-by-case basis
Vertical or
horizontal; to be
Vertical or horizontal; to
Orientation
Vertical
Vertical
Vertical
determined by City
be determined by City
on a case-by-case
on a case-by-case basis
basis
Gear
Operator
No
No
Yes
Yes
Yes
Required
Vault
No
No
Yes
Yes
Yes
Required
Bypass
No
No
No
Yes
Yes
Required
26
Section 3
Water and Wastewater Criteria Manual
3.17.1.3 Details
Refer to Drawings W104, W105, W1 06A, W10613, and W601 on Sheets 1 and 2 of the
City Standard Details.
3.17.2 Air Release Valves and Air / Vacuum -Air Release Valves
For water mains less than 16" diameter in certain situations where the topography,
remoteness, or some other hydraulic factor necessitates it, air release valves are required
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 high
points to facilitate automatic release of accumulated air and to facilitate automatic
prevention of vacuum conditions within the line. See Drawings W801 and W802 on Sheet
3 of the City Standard Details.
3.17.3 Pressure Regulators
In areas where pressures may exceed 80 psi, builders and plumbers should be advised
that in such locations pressure reducing devices should be installed in accordance with
the current Plumbing Code adopted by the City of Denton. Pressure reducing valves will
not be installed in the public water system.
3.18 Dead-end Mains
Dead-end main situations should be avoided whenever possible. These situations create
a stagnant water condition that can cause taste and odor problems as well as low chlorine
residuals. These mains create maintenance problems, because they must be routinely
flushed, In addition, dead end mains result in a waste of water resources due to required
flushing to ensure water quality.
In lieu of dead-end mains, the design should loop through public right-of-way or a
dedicated public utility easement (with adequate assurance of access and fencing
prohibited) 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 device
near the main's end and past the last service connection.
It is recommended that a dead-end main should have no more than one fire hydrant
connected to it. If the length of the dead-end main is such that a fire hydrant is required
along it, then the design engineer should consider if any additional fire hydrants need to
be placed on the cross feed mains. See Figure 3.8 in Drawing PIAZ16 on Sheet 2 of the
City Standard Details.
3.19 Fire Hydrant Locations and Coverage
The design engineer should locate fire hydrants as close as possible to street
intersections, but outside of the curb radius. This positioning of fire hydrants provides
coverage along several streets. When spacing requirements necessitate the installation
of fire hydrants between street intersections, they should be placed at the projection of lot
lines between property owners. For main replacement projects in established
neighborhoods, fire hydrants should be designed as close as possible to the old fire
27
Secrion 3
1 if— and Vli tevvater Criteria Manua
hydrant location, provided coverage is adequate. Neighborhood residents are familiar
with the fire hydrant being at that location and normally expect a replacement fire hydrant
to be placed at the same location. Fire hydrants are not to be installed closer than nine
(9) feet to any wastewater main or any wastewater appurtenance.
As a general guideline, fire hydrants shall be placed at a maximum of 600 feet apart in
residential areas and a maximum of 300 feet apart in commercial (including apartments)
and industrial areas.
3.20Requirements for Abandoning Wafer Mains
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 any proposed water
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 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 main prior to
the new main's placement into service, then provisions for a temporary water main with
services must be addressed by the design.
Typically, abandoned lines may be left in place with only the ends being plugged or
capped. However, the City may require special abandonment actions including, but not
limited to, filling the abandoned water main with grout, removal and proper disposal of all
above ground appurtenances, and removal and proper disposal of the abandoned pipe.
3.20.1 Replacement Mains
On mains being abandoned, the design engineer shall note and locate points of cut and
plug as close as possible to the main that remains in service. (See Figure 3.9 in Drawing
PIAZ16 on Sheet 2 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 in Drawing
PIAZ16 on Sheet 2 of the City Standard Details).
3.20.3 Fire Hydrants
Fire hydrants located on mains being abandoned shall be removed and delivered to the
City of Denton Water Utilities Department.
3.21 Flushing and Disinfection
Prior to making permanent connections to the distribution system, water distribution
mains, valves and appurtenances shall be adequately flushed and disinfected in
accordance with the most current revision to AWWA C651, and bacteriological testing
shall be completed to meet the standards established by the Water Utilities Department
and Chapter 290 of the Texas Administrative Code (30 TAC §290). Additionally, heavily
chlorinated water shall be flushed from all segments of the newly constructed mains before
final connections are made.
W
Section 3
Water and Wastev,e.-Iter Criteria Manua!
Before commencement of construction of water distribution infrastructure, the Contractor
or engineer shall submit a flushing and disinfection plan to the Department of Water
Utilities for review. Ata minimum the plan shall describe:
A. Flushing procedures
B. Hydraulic calculations to demonstrate adequate flushing velocities, or
demonstrate conformance with the conditions outlined in AWWA C651 Table
3.
C. The method of chlorination
D. Bacteriological sampling plan
E. Dechlorinating procedures (Ref. AWWA C655)
F. Disposal of chlorinated water
29
Section Y
Water and Wastewater Criteria Manual
Section 4 — Wastewater Design Guidelines
4.1 General
It is the responsibility of the design engineer to ensure the final design of a sewer main is
in conformance with the following:
A. Texas Administrative Code (TAC) Title 30, Part 1, Texas Commission on
Environmental Quality (TCEQ) — Rules, Ch. 217, "Design Criteria for Domestic
Wastewater Systems"
B. Denton Development Code (DDC)
C. This Manual and the City's Standard Detail Drawings
D. North Central Texas Council of Governments (NCTCOG) Standard Specifications for
Public Works Construction ("COG Specs."), as amended by the City of Denton
E. City of Denton Wastewater Master Plan
4.2 Estimated Wastewater Flows
A. For sewers in new developments, sewer lines and lift stations shall be designed to
accommodate the projected buildout flows from all residential, commercial, industrial,
or institutional sources upstream of the proposed sewer improvement. Figure: 30 TAC
§217.32(a)(3) Table B.1. - Design Organic Loadings and Flows for a New Wastewater
Treatment Facility (see excerpted information in Table 4.2-1) shall be used as a guide
to generate wastewater flows. However, minimum flow capacity for sizing of sewers
for peak flow condition shall not be less than the results of the following calculation
procedures:
1. Delineate the wastewater drainage area that will drain into the sewer main or lift
station. Include all upstream offsite areas.
2. For the development site, use the following design parameters:
a. Table 4.2-1 to generate the wastewater loading by type of use.
b. 3.2 capita per lot for single family.
c. 2.5 capita per unit for multifamily.
d. Apply a 4.0 multiplier to the average daily flow to determine the peak flow.
3. For undeveloped upstream areas, use the following design parameters:
a. 4 lots per acre.
b. 3.2 capita per lot.
c. Average daily flow of 100 gal/capita/day.
d. Apply a 4.0 multiplier to the average daily flow to determine the peak flow.
4. For developed residential upstream areas, use the following design parameters:
a. Count number of single family lots.
b. Obtain number of multifamily units (available through DCAD)
c. 3.2 capita per lot for single family.
d. 2.5 capita per unit for multifamily.
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
5. For developed non-residential upstream areas, use the following design
parameters:
a. Average daily flow of 1500 gpd/acre.
b. Apply a 4.0 multiplier to the average daily flow to determine the peak flow
30
Section 4
Rer and Wastewater Criteria Mantra!
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 City
sewer shed computer models.
TABLE 4.2-1
ExcerptDesign
(reproducedTreatment Facility
Table IBA)
Daily Wastewater
Flow
Source
Remarks
Gal. Per Person)*
Municipality
Residential
75-100
Subdivision
Residential
75-100
Trailer Park
2'/ Persons
Transientper
Trailer
50-60
Mobile Home Park
3 Persons per Trailer
50-75
Cafeteria & Showers
20
School
Cafeteria/ No Showers
15
Overnight User
30
Recreational Parks
Day User
5
A facility must be
Office Building or
designed for the
20
Factory
largest shift
Hotel/Motel
Per Bed
_
50-75
Restaurant
Per Meal
7-10
Restaurant with bar
or cocktail lounge
Per Meal
9-12
Hospital
Per Bed
200
Nursing Home
Per Bed
75-100
Alternative
Collection Systems
Per Capita
75
e.g., septic tanks
X City of Denton requires usage of the highest number of the
TCEQ ranges.
4.3 Separation Distances between Wastewater Collection System Pipes and
Manholes and Public Water Supply Pipes
Wastewater mains and manholes shall be separated from water mains as set forth in
Texas Administrative Code (TAC) Title 30, Part 1, Texas Commission on
Environmental Quality (TCEQ) Rules - 30 TAC §217.53.d Separation Distances.
31
Section 4
Water and Wastewater Criteria Manual
4.4 Size and Sone 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 than service
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.
V= 1.49 (R) 0.11 (S) 0.e0
n
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 per
foot)
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 acceptable Manning'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. The sewer
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 • 'in
Inches I.D.
MinimumSlope
In Percent
MaximumSlope
Percent
Full at Min. Slope
8
0.335
8.40
0.45
10
0.25
6.23
0.71
12
0.20
4.88
1.03
15
0.15
3.62
1.62
18
0.115
2.83
2.25
21
0.095
2.30
3.07
24
0.08
1.93
4.14
27
0.07
1.65
4.91
30
0.06
1.43
6.23
33
0.055
1.26
7.66
36
0.045
1.12
9.17
32
Section 4
v! MFf m-F^r Cri!aria I1.:1 ri�i31
The capacity of the sewer pipe flowing full shall be computed by the following equation:
C = 0.299 (D) 2.11 (S) oso
n
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)
4.4.1 High Velocity Protection
Where 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 restraint systems must
be utilized.
4.5Sewer 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 the
proposed main and including an additional two foot drop. Therefore, for a house 100 feet
from the proposed sewer main, the designed depth of the main shall be at least 4.0 feet
below the finished floor elevation of the house since:
2 feet + (2% of 100 feet) = 4.0 feet
The 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 to serve 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 cover
shall be 3.5 feet. Any main approved to have less than minimum cover shall be encased
in Class "G" embedment. See Drawing U204 on Sheet 7 of the City Standard Details.
When establishing depth for proposed wastewater mains, design engineers shall consider
the impact of proposed water and drainage improvements especially on service laterals
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. For new construction in areas not served, sewer mains shall be laid straight between
manholes. No horizontal or vertical bends are allowed between manholes.
B. Avoid shifting mains from one side of the ROW to the other side of the ROW between
street intersections.
C. Where the bypass of existing flows is feasible, it is recommended that replacement
mains be constructed horizontally in the same trench.
33
Section 4
Water and Was'evvater Criteria Manua/
4.8 Sewer Laterals
Minimum lateral sizes from the sewer main to the public cleanout are:
A. 4" minimum for single family
B. 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 Sheet
5 of the City Standard Details.
Manholes shall be provided for lateral connections when the lateral pipe diameter is equal
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 less
than 1% grade.
4.9 Gravity and Force Main Sewer Pipe Material
Gravity and Force Main sewer pipe shall meet the following criteria unless special
circumstances require an alternative and is approved by the Director of Wastewater
Utilities.
Table 4.9-1
Size
Application
Pipe Material
PVC — ASTM D3034, SDR 35
8 in. through 12 in.
Gravity
(for pipe depths 15 ft., or greater, use SDR -26 pipe)
HDPE — ASTM D3350, DR -17
15 in.
Gravity
PVC — ASTM D3034, SDR 35
(for pipe depths 15 ft. or greater, use SDR -26 pipe)
18 in. through 24 in.
Gravity
PVC — ASTM F 679, PS46 or PS115
Fiberglass Reinforced Plastic — ASTM D3262
6 in. through 60 in.
Force Main
HDPE — ASTM D3350, DR -13.5
DIP —AWWA C150/C151, CL52 or PC 350, epoxy interior lining
For gravity sewer pipe sizes over 24" in diameter, design calculations and pipe selection
shall be submitted by the development design engineer for review; approvals will be
provided on a project specific basis.
0
Section 4
Wager and +Nastewater Crfterfa Manual
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 be
submitted by the development design engineer for review.
Different pipe materials shall not be mixed between manholes. If it is anticipated that a
mixing of materials will occur, the design engineer shall design a manhole at the point of
transition 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 Sheet 7 of the City Standard Details. Embedment requirements
shall be based on sewer mains under proposed pavement, unpaved areas and existing
pavement.
Embedment and backfill up to six (6) in. above the top of the pipe will be based on
materials as specified by North Central Texas Council of Governments (NCTCOG)
Standard 504.2.2.1(a). Crushed stone embedment — Aggregate Grade 4.
Table 4.10-1
ovanuaro
Aggregate
Retained on 1 -'/2 inch sieve
0%
Retained on 1 inch sieve
0-5%
Retained on'/ inch sieve
40-75%
Retained on No. 4 sieve
90-100%
Retained on No. 8 sieve
95-100%
4.11 Manholes
Manholes constructed on existing or proposed sewer lines shall be sized as follows:
Table 4.11-1
4.0 ft.
8" through 12" (For depths greater
than 12 ft., use 5.0 ft.
15" through 27" 5.0 ft.
30" through 36" 6.0 ft.
Special manholes shall be designed
for mains larger than 36" diameter pipe.
35
Section 4
Water anrf IAV aste?rjafo, r Critsufa Manual
The types of manholes allowed by the City are shown in Drawings S101, S102, S103 and
S107B of Sheet 4 of the City Standard Details.
Generally, manholes shall be stationed on the main run, and where known, the stations of
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 the outfall main
level with the top inside elevation of the proposed main.
4.11.1 Manhole Locations
Manholes shall be provided at the following locations to facilitate maintenance, cleaning,
and inspection:
A. At the location of lateral connections that are 8" in diameter or larger.
B. At 500 feet intervals on sewer mains 15" diameter or smaller; at 800 feet internals on
mains 18" diameterthrough 30" diameter; at 1,000 feet intervals on mains 36" diameter
through 48" diameter; and at 2,000 feet for 54" diameter and larger.
C. At all locations where pipe diameter or pipe material changes.
D. At all locations where the horizontal or vertical alignment of the sewer main changes.
E. At the ends of all mains with service connections. Two ends of a main may not be
combined in one manhole.
F. 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 Drawing S402 on Sheet
5 of the City Standard Details.
G. At the end of any pipe segment at least 150 feet long.
H. Sewer service laterals are to be connected to the sewer main line and not into a
manhole unless it is a size on size connection.
I. 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.
J. 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 of the
appropriate regulatory agency. Crossings shall meet the requirements made by the
controlling agency and by City of Denton Standards. In the event of different requirement
levels 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 the
appropriate railroad company and regulatory agency and determine if there are any
special requirements. In the event City of Denton Design Criteria are more stringent than
those of the Railroad Company or regulatory agency, the City's standards shall apply. See
Section 6.4.A for processing of railroad permits.
36
Section 4
Water and Wastewater Criteria Manual
4.14 Tunneling, Baring, Jacking and Casing
Tunneling, boring, jacking and casing are methods used for sewer line placement under
restrictive 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 receiving pits
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 of pipe. Width
of the bore pit can vary depending on the depth and size of pipe, with the narrowest width
being approximately 15 ft. The preferred location for the bore pit is the lower elevation
end of the bore; allowing any groundwater and/or boring slurry to drain from 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, shall
have an inside diameter (ID) large enough to accommodate a carrier pipe of at least two
(2) standard sizes above the pipe being installed and shall meet the minimum ID listed in
Table 4.14-1. The casing pipe wall thickness design shall be based on the requirements
of the agency whose facility is being crossed and shall conform to the minimum criteria
listed in Table 4.14-1. Casing pipe shall be provided with interior and exterior coal -tar
protective coating in accordance with AWWA C203. Field welds shall be coated with an
equivalent coating.
Table 4.14-1
Nominal Carrier .•
Size a
8 in.
Minimum Casing Pipe
0
Minimum Casing Pipe
Wall Thickness
3/8 in.
12 in.
12 in.
20 in.
1/2 in.
16 in.
24 in.
1/2 in.
20 in.
30 in.
1/2 in.
24 in.
36 in.
5/8 in.
30 in.
42 in.
5/8 in.
>30 in.
b
c
a. Minimum death of
bore shall be 42 inches.
b. Consult with the Department of Water Utilities
c. Project specific design must be sealed and signed by a Professional Engineer
licensed by the State of Texas
Force mains through casings shall follow the same requirements as are laid out for water
mains in section 3.11 of this manual.
4.15Underground Utility Crossings
The requirements of Section 3.13 of this manual shall govern the crossing of underground
utility lines by wastewater mains.
37
Section 4
.:--. &:-J WastewaterCn'teria Manual
4.16 Fence or Wall Crossings
The requirements of Section 3.14 of this manual shall govern the crossing of fences or
walls by wastewater mains.
4.17 Creek Crossings
When a sewer main crosses a creek or channel, the design engineer must evaluate the
condition of the creek bed and ensure erosion control is provided. Backfill material and
minimum construction criteria are shown in Low Water Channel Crossing Drawings S701
and S702 on Sheet 6 of the City Standard Details. These criteria include creek bed soil
and condition, as well as presence of exposed rock.
4.18Siphons
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 of
Water Utilities. Inverted siphons shall not have less than two (2) barrels, with a minimum
pipe 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 the
siphon with adequate clearance for maintenance and cleaning purposes. Bank and
channel stabilization may be required to protect the crossing lines and casing of the carrier
pipe may be required to meet environmental or other restrictions.
4.19 Abandonment of Sewer Mains
The design engineer should note the limits and appropriate conditions for the abandoning
of existing wastewater mains which are to be replaced by the construction of any 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 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 main prior to
the new main's placement into service, then provisions for a temporary wastewater main
with services must be addressed by the design.
Typically, abandoned lines may be left in place with only the ends being plugged or
capped. However, the City may require special abandonment actions including, but not
limited to, filling the abandoned wastewater main with grout, removal and proper disposal
of all above ground appurtenances, and removal and proper disposal of the abandoned
pipe. In situations where a manhole is being left in service even 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 determines that the pavement is in good
condition the City may allow the abandoned line to be plugged from inside of the manhole.
G
Section 4
' Vater and Wastewater Criteria Manual
4.20 Abandonment of Manholes
If a manhole as well as the sewer main is to be abandoned, the method described is
Section 4.18 above, along with the minimum guidelines shown in Drawing S105 on Sheet
4 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 analysis of
the physical and economic factors involved. A Preliminary Engineering Report is required,
which lists all factors and adheres to current state regulations. The City reserves the right
to review each proposal and determine whether there is enough merit to justify a lift station.
4.21.1 Preliminary Design Submittal
A preliminary design submittal is required for each lift station proposed. The submittal
shall include a written report and a map prepared by a Professional Engineer licensed by
the State of Texas.
A. The plans submitted shall contain the following information, as a minimum:
1. Be to scale, with the scale indicated.
2. A north arrow.
3. A location map.
4. Delineation of the boundary of the proposed development.
5. Delineation of the boundary of the sewer shed in which the development lies.
6. The area in acres of the development.
7. The area in acres of the sewer shed contributing to the Lift Station.
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 Sensitive
Areas (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 that
warrant a lift station.
2. Influent hydraulic calculations showing:
a. Area in acres of the sewer basin and the development.
b. The area of each proposed land use for the development and for the projected
land use(s) for the basin.
c. The design flow for the basin and the development.
d. The maximum flow for the basin and the development.
e. Elevation of the proposed lift station site.
f. The elevation of the proposed discharge point of the force main.
3. Preliminary wet well volume calculations.
4. Preliminary force main size.
39
Section 4
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 accessible
during 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) ft. high, opaque
concrete or masonry wall, with an opaque sliding gate, minimum of sixteen (16)
ft. on track flush with the ground. All shall be of an architectural style and colors
blending with the development architecture, as approved by the city.
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 sewer basin
as possible. This may require the station to be located off-site of the development.
When it is required the station serve a larger area than the 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 to the system.
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 dry
well, 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 large
enough 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 an aluminum
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 and frame shall
be Bilco Type K, KD or an approved equal.
7. The wet well, dry well, valve vault and meter vault, including decks, shall all be
cast in-place concrete only. No other materials are acceptable.
40
Section 4
Mer and Wastewater Criteria Manual
8. The coating for the wet well exterior and interior walls shall be coated as specified
in 4.21.2.0 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 evaporation will 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.
C. Exterior Walls (below grade, to be backfilled)
Table 4.21-1
Tnemec Series 46H-413
Polyamide Epoxy - Coal
Tar
Clean and Dry
8 - 10 mils in two coats
for a total of 16.0 to 20.0
dry mils
D. Interior Walls (Thick Film System)
Table 4.21-2
In addition to this coating system, the lining products listed in
Drawing S101 of the City Wastewater Standard Details are acceptable.
E. Site Access
1. Access will be provided by an all-weather surface of flex -base or better from a
public street to the station site.
2. Access shall be functional during a 25 -year flood. The road surface shall be
above 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 -around
adjacent to the lift station, sized large enough to accommodate a City service
truck with generator.
41
Section 4
A19ter Fnd 111,f?stevi?ter Criteria Maoua!
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 or
flex -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.
4.21.3 Hydraulic Design
A. Influent Flow
The preliminary design report shall include the design flow and the maximum flow for
the development and the sewer basin. The design flow shall be calculated in
accordance 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 entire
sewer basin. If the sewer basin is significantly larger than the proposed
development and it is not feasible to design for this flow, the firm pumping capacity
may be designed to handle a portion of the basin with approval from the Director
of Water Utilities.
3. The pump curves shall be selected so the pumps will run near the best efficiency
point during normal operating conditions. The selected curves shall also be such
that the pumps do not approach shut-off head when they are running
simultaneously.
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 modified pump
curves.
C. Wet Well Volume
1. Wet well volume for a submersible pump station is the volume contained above
the top of the motor, or as specified by the pump manufacturer, to the bottom of
the influent pipe. TCEQ Rule §217.60(b)(4) (d) A gravity pipe discharging to a
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wet 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 volume
contained 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 the
wet 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:
T= V + V
D -Q Q
Where:
T = Total time between successive pump
starts in minutes (operating cycle)
D = Rated pump capacity in GPM
V = Storage volume between lead pump on
and pump off elevations in gallons
Q = Inflow to wet well in GPM
The operation cycle 'T' shall not be less than
10 minutes for Average Flow and not more
than 60 minutes for Minimum Flow
conditions.
4. Per TCEQ Rules, 30 TAC § 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 60
months, or at least 20 minutes, whichever is longer. The design must be based
on 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 be
used to provide backup power, then the owner must have a contract in place that
guarantees fuel supply during an emergency. The owner must also have
sufficient storage capacity at the wastewater treatment facility for the fuel for the
duration of the emergency.
(h) For calculation purposes, the owner must assume that the lift station wet well
is 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 from the
Director of Water Utilities. The minimum force main size shall be four (4) inches in
diameter, except for Grinder Pump lift stations. The minimum recommended velocity
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.
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V/aFarapd OAstewager Diterfe Manual
4.21.4 Pumps
Acceptable pumps are listed in the City of Denton Approved Products and Materials List.
4.21.5 Mechanical
A. 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 the
Director of Wastewater Utilities.
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 a primer
layer of 5 mils thick fusion bonded epoxy and 55 mils thick of modified DuPont
Fusabond Polyethylene, or approved equal.
3. Force mains shall be laid to Denton Standard Construction Specifications.
4. Plans shall include plan and profile for the force main, including valves every 2000
feet per TCEQ 217 rules.
5. All force main contractors shall furnish and install non-metallic pipe detection tape.
The pipe tape shall be green, 6 -inch wide, 4 mils thick with 3 -inch black
continuous lettering "Caution Sewer Line Buried Below." The pipe tape shall be
per TCEQ requirements:
i A detectable underground warning tape must be laid in the same trench as
a force main pipe. The detectable underground warning tape must be
located above and parallel to the force main.
ii The detectable underground warning tape must bear the label
"PRESSURIZED WASTEWATER" continuously repeated in at least 1.5
inch tall letters.
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 consists
of a primer layer of 5 mils thick fusion bonded epoxy and 55 mils thick of modified
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 from the
approved materials list, meeting the City of Denton Standard Construction
Specification.
Section 4
Witr-r and Wastewater Criteria Mantia?
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 or a
ball check. There must be at least 15 feet of vertical head downstream in order to
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 the isolation
valve in a separate vault. For self -priming stations, a check valve shall be located
in the building. Under no circumstance shall the check valve be allowed 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 installed along
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 and vacuum
breaker (see Drawing S803 on Sheet 6 of the City Standard Details). The design
engineer shall determine the type and location, subject to approval of 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 and profile
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 placed into
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.
4.21.6 Electrical, Instrumentation and Supervisory Control and Data Acquisition
(SCALA) Requirements
The City of Denton Water Reclamation department performs the build and install of
SCADA and telemetry packages. Developers should request the packet and COD will
provide a bill of materials for this service.
Section 4
Water and Wastewater Criteria Mantaai
4.22 Low Pressure Collection S
Low pressure collection systems may be allowed with specific approval by the Director
of Wastewater 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 TCEQ Rules, 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 criteria listed in this Section, and Sections
35.11 and 35.12 of the City of Denton Development Code.
4.23.2 Permits Required
Any owner of a residential, commercial or institutional building who utilizes an on-site
sewage 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 of land. 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 Requirements
A 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 the following
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.
section 5
Water and 111fastewater Criteria Manual
Section 5 — Construction Plans
5.1 General
Before any public works construction relative to a development may begin, City staff will
verify the construction plans have been approved. Construction may not begin until the
construction plans have been approved, all fees (including review and inspection fees)
have been paid, all necessary agreements and bonds have been provided, and a Pre -
Construction Conference has been held by the City.
5.2Responsibility
The sealing engineer is responsible for the accuracy, completeness, and conformance of
the submitted plans to City standards. The purpose of the City review is to ensure
conformance to City policies and standards. The City review is limited to facts as
presented on the plans submitted. The City has no project engineering design or quality
control review responsibility. The engineer certifying the plans is responsible for the
accuracy and completeness of the plan documents. The City reserves the right to require
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 of
22 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 on
North America Vertical Datum 1988 (NAVD 88). Only NAVD 88 shall be used for plan
elevations; 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 corresponding
vertical 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 and
proposed underground utilities. 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 Systems
Plan sheets must show the horizontal alignment of the proposed water system within
street rights-of-way and easements, with horizontal control points for location of the rights-
of-way and easements and for location of the water system within the rights-of-way and
easements. Sizing of pipe, valves, fittings and appurtenances must be shown on the plan
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Water and W stetvater Criteria Monuai
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 showing proposed 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. Approved variances (if any) from City
Standard Details must be provided. Show all service lines up to 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 be shown to indicate planned
crossings of utilities, storm drains, and stormwater facilities and potential conflict points.
5.4.3 Sanitary Sewer Systems
Plan sheets must show the horizontal alignment of the proposed sanitary sewer system
within street rights-of-way and easements, with horizontal control points for location of the
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 must
be shown on the plan view. Manhole rim elevations, and pipe "in" and "out" elevations
must 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. Every
sanitary 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. Approved
variances (if any) from City Standard Details must be provided. The plan view shall include
arrows indicating direction of flow in pipe. Show all service lines to and including the 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 conflict points.
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
water directional arrows to define the flow patterns.