13-09-003

Arizona Revised Statutes establishes the control for water system design with the Arizona Department of Environmental Quality (ADEQ). Engineering bulletins produced by ADEQ are to serve as guides for water system design along with other criteria established by the City. Pertinent Engineering Bulletins include, but are not limited to:

A. Bulletin No. 10 - Minimum Basic Design Criteria for Construction of Water Distribution and Water Treatment Systems.

B. Bulletin No. 8 - Disinfection of Water Systems. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0002 Extension and Network Design

A. Any extension of a water line or network of water lines shall be designed to provide for required fire flows and peak hour flows (in accordance with Section 13-09-003-0004) simultaneously with no residual pressures in the system dropping below twenty (20) psi. In order to assure that a twenty (20) psi residual pressure within the public system is maintained, a minimum static pressure of forty (40) psi is required at the highest point within the public system.

1. Future extension of a proposed system will increase the possibility of residual pressures dropping below twenty (20) psi.

2. System analysis is required and shall include anticipated future expansions.

B. Water mains shall be designed to maintain between forty (40) and one hundred thirty (130) psi during peak hour demand conditions at a flow velocity of less than or equal to five (5) fps, or they are to maintain a pressure greater than or equal to twenty (20) psi at a point of maximum fire flow, at a flow velocity of less than or equal to ten (10) fps.

1. The pipe diameter shall be the largest diameter calculated for the two (2) conditions above.

C. The maximum allowable head loss for transmission lines is eight (8) feet per one thousand (1,000) feet and ten (10) feet per one thousand (1,000) feet for distribution lines.

D. Required water pipe sizes will be determined by a network analysis (Hardy Cross or equivalent), but in no case will public lines smaller than eight (8) inch diameter be permitted (in connection with a grid network).

1. A new minimum eight (8) inch main is required if the existing main is less than six (6) inches and a new or larger service (even a three-quarter (3/4) inch) is required.

a. A six (6) inch diameter pipe may be permitted only in special cases (such as dead end stubs-outs less than ninety (90) feet which have no potential for extension), with approval of City Fire Department, Utilities Division and Engineering Section.

2. All dead end systems longer than one thousand (1,000) feet, or with more than three (3) fire hydrants, shall have two (2) or more connections to an existing main, and the main shall have at least one (1) valve between the connections.

3. Fire hydrants shall be served from an eight (8) inch or larger water line and, depending on distance, may be required to be off a looped line.

E. Performance of a planned network shall be based on the existing pressure zones of the City water system. System designs must be adequate for extreme cases; e.g., reservoirs near empty, peak hourly demands in effect, and the required fire flow.

F. Where reasonable, water mains shall be located under a paved surface. Where this is not possible, the engineer should give consideration to access and maintenance issues. The engineer should examine the possibility of redesigning the project layout, e.g., roads, building envelopes, and drainage patterns, in order to facilitate access and maintenance to all water pipes and appurtenances. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0003 Water System Overview

A. Pressure Zones.

1. Approximately five (5) operating pressure zones serve the municipal distribution system for the City of Flagstaff. These zones operate nominally within a static pressure range between forty (40) to one hundred thirty (130) psi.

2. With regard to typically high seasonal water demand variations among pressure zones with elevated storage, operating pressure fluctuations are normal. Information on pressure zones serving the various areas of the City can be obtained from the City of Flagstaff Utilities Division. All pressure zones have elevated storage within the City of Flagstaff.

3. In areas where a static pressure in excess of eighty (80) psi is realized, individual pressure reducing valves are required to be installed and maintained by the owner/developer in accordance with the International Plumbing Code. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0004 Water Demand Criteria

The City of Flagstaff municipal water system has dual functions. It supplies potable water for industrial, commercial and domestic use and supplies water for fire protection. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0004.1 General

Minimum pipe sizes shall meet the criteria established in Section 13-09-003-0002; however, may not be adequate to meet all system water demands. For some projects, a detailed analysis of domestic and fire flow demands may be required to properly define requirements for system design. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0004.2 Domestic Demand

For the purposes of system design the Utilities Division has established factors for maximum daily consumption for various domestic uses. Although the list is not all-inclusive, it does serve to establish a general baseline for system evaluation and analysis. Table 13-09-003-01, and Table 13-09-003-02, Water Demand Criteria, show the water demand factors to be used for the determination of maximum daily consumption. No allowances for fire protection or fire flows are included in these factors. For information not included herein, the designer shall contact the Utilities Division for consultation and agreement on design demand.

All water mains are to be designed using the following tables from the City of Flagstaff "Water System Improvement Program" report (November 1980) and ADEQ Bulletin No. 12.

Table 13-09-003-01

Average Population Densities
Type of dwelling units	Number of persons/unit
Mobile home	3.0
Single-family	3.5
Multifamily	2.5
Hotel/motel	2.0

Table 13-09-003-02 Water Demand Criteria
LAND USE	AVERAGE	PEAK
Residential Single-Family, Low Density	120 gpcd	300 gpcd
Residential Single-Family, TH Medium Density	100 gpcd	250 gpcd
Residential Apartments, Condos, High Density	75 gpcd	250 gpcd
Hotel, Motel Tourist	75 gpcd	200 gpcd
Commercial	2,000 gad	5,000 gad
Industrial	2,000 gad	5,000 gad
gpcd = gallons per capita per day
gad = gallons per acre per day
FROM CITY OF FLAGSTAFF "WATER SYSTEM IMPROVEMENT PROGRAM"

NOTE:	If a proposed development does not fit within the categories listed above, a maximum daily consumption of 200 gallons per person per day shall be used. For clarification, the following example characterizes the calculations performed to determine the design flows and quantities involved in a hypothetical system design.
EXAMPLE:	Hypothetical water demand/flow evaluation
ASSUME:	A 120-dwelling unit, medium density, residential subdivision development
CRITERIA:	From Table 13-09-003-01, and Table 13-09-003-02, Water Demand Criteria, population density = 3.5 persons per dwelling unit
Maximum daily consumption = 250 gallons per capita per day (gpcd)
Design population = 120 x 3.5 = 420 people
Maximum total daily consumption = 250 x 420 = 105,000 gallons per day (gpd)
Peak day flow rate = 105,000 gpd/1,440 mpd = 72.92 gpm

It is stressed that fire flow requirements are not included in the above example. The calculated flow rates and quantities shall be added to the required fire flows prior to the design of water mains, booster pumps, storage reservoirs and other system components. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0004.3 Fire Flow Demand

A. Required fire flow and peak day flow rate shall be available in the system. Municipal fire flow required by the City for any one (1) particular location varies depending on the land use. The number of hours that the required fire flow shall be available also varies depending on the land use and ranges from two (2) to ten (10) hours.

B. When a reservoir is to provide a second source of water to a development, the capacity shall include the sizing necessary to provide the required fire flows for a minimum of two (2) hours. Reservoir supplement shall meet Utility Department approval.

C. The increased use of automatic extinguishing systems, whether they use water or some other agent, will affect the quantities of water required. Table 13-09-003-03, Minimum Fire Flow Requirements, outlines the required fire flows. Fire sprinkler demands are in addition to the flow requirements shown in Table 13-09-003-03, Minimum Fire Flow Requirements. Flows in the table represent the fire flow of the public system at fire hydrants. It shall be noted that the Fire Department may require a fire flow greater than shown in the table due to building construction materials, contents, or other factors. These cases require consultation with Utilities Division and Fire Department staff.

Table 13-09-003-03

Minimum Fire Flow Requirements
1,000 gpm for single-family residential
1,500 gpm for multifamily residential
1,500 gpm for commercial and industrial areas

(Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0005 Valve Locations

A. Valves shall be located in the network so that no single accident, breakage, or repair to the system will necessitate the removal from service of a length of pipe greater than five hundred (500) feet in high value (commercial, industrial) districts. Sufficient valves shall be provided on water mains to minimize inconvenience, degradation of fire protection and sanitary hazards during repairs. Variations in this spacing may be required for special applications. Valves are to be located so that no closure of a valve on a main line is required unless there is breakage on the main itself.

B. Valves shall be generally located as follows, unless otherwise approved by the Utilities Division:

1. At intervals to isolate no more than two (2) fire hydrants at any time.

2. At minimum intervals of five hundred (500) feet in commercially zoned areas and residential off-site water mains.

3. In residential areas to isolate a maximum of thirty (30) services (approximately six hundred (600) feet).

4. At minimum intervals of eight hundred (800) feet for transmission lines.

5. Valves shall not be located in street gutters, valley gutters, concrete aprons, or in driveways.

6. Three (3) valves are required on a four (4) way cross, two (2) valves minimum are required on all three (3) way tee fittings.

C. The valve location is to be a minimum of ten (10) feet upstream of the cap or blow-off assembly.

D. Every fire hydrant is to have a valve on the lead line.

1. Blow-off valves are required at the ends of dead end lines, whether temporary or permanent.

a. When a fire hydrant is required at or near the end of a dead end main, it shall be installed at the end of the main instead of a blow-off.

2. No fire hydrant or water services will be allowed on the water line between temporary blow-off valves and the plug. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0006 Valve Box Assembly

A. All valve boxes shall be DOMESTIC (nonimport), Tyler Series No. 6855 or East Jordan Iron Works Model No. 8555 or equivalent, having a minimum shaft diameter of five (5) inches ID, and lid marked "WATER."

B. Valve boxes shall be sliding, adjustable, with lip on all sections. No lock type, screw type, cast iron no-hub sewer pipe, caulder couplings, bands, tin, gaskets, grout, or any other material will be allowed in valve box assemblies.

C. No butt-joints will be allowed. All sections shall have a minimum of two (2) inch overlap.

D. No bricks will be allowed around a valve.

E. Center the valve box over the valve. No part of the box should contact the valve. Material around the valve shall be compacted to ninety-five percent (95%).

F. Fill material shall be compacted to ninety-five percent (95%) around valve and valve boxes up to finished grade in one (1) foot lifts.

G. If a valve nut, whether existing or new, ends up to be sixteen (16) inches or less from finish grade, one (1) top section box, with lip, of appropriate length will be allowed.

H. If any contractor has to adjust to grade a new or existing valve box for any reason, the adjustment will start from the valve nut up to finished grade to eliminate any existing broken, dirty, cracked, crooked, too small, or otherwise substandard valve boxes.

I. If a bottom section is in good condition, clean and centered, it can remain but the old top section will be removed to allow for additional bottom sections and a top.

J. Two (2) piece valve box assemblies are preferred as shown in Engineering Detail 9-03-060, Figure A. Bottoms come in lengths of up to sixty (60) inches. Tops come in lengths of up to twenty-six (26) inches.

K. Another option is adjusting with one (1) or more bottom sections and a top section as shown in Engineering Detail 9-03-060, Figure B.

L. Valves not located in the street will be marked by a blue, two and one-half (2-1/2) inch by seventy-two (72) inch "Carsonite" valve marker with concrete ring. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0007 Water Services

A. All pipe and fittings for water services shall have a minimum pressure rating of two hundred (200) psi.

1. Where not otherwise noted on the plans, all water services shall be at least three-quarters (3/4) inch I.D. and shall have a minimum cover of thirty (30) inches and a maximum depth of forty-eight (48) inches except for the last two (2) feet adjacent to the curb stop.

B. The location of water services shall be installed branded on top or face of curb with a "w."

C. Other utilities such as phone and electric shall be a minimum of four (4) feet from the water service including no crossings near the curb stop.

D. Installation of three-quarters (3/4) inch and one (1) inch curb stops shall include a brass plug to protect the threads and keep out dirt.

E. Restrictions.

1. Water services are not allowed on transmission mains that are sixteen (16) inches or larger, fire sprinkler lines or on the six (6) inch lead line between the six (6) inch valve and the fire hydrant on fire hydrant assemblies.

2. Only one (1) meter per lot, three-quarters (3/4) inch maximum, is allowed on existing two (2) inch water lines.

3. No multifamily or commercial connections may be made on a two (2) inch line. No more than sixteen (16) three-quarters (3/4) inch meters will be allowed on any two (2) inch diameter water main.

F. Water services, meter, and box shall be installed perpendicular (not parallel) to the main line, within the right-of-way or easement, and shall not be installed across another’s private property. Water service lines between a water main and water meter shall be installed perpendicular to the water main unless otherwise approved by the City Engineer.

G. When an existing water service is required to be abandoned, it shall be abandoned at the main. The saddle and corp. stop shall be removed in the main clamped with an approved full circle repair clamp. In the event the meter is no longer needed, it shall be salvaged to the Utilities Division. When an existing water stub is to be abandoned, it shall be abandoned at the main, the valve removed, and a blind flange installed on the tee.

H. Gas service lines installed jointly with a water service need to be separated the last three (3) feet to allow a minimum separation of two (2) feet between curb stop and gas line; or the PE gas line must be sleeved inside a pipe Schedule 40 or greater. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0007.1 Copper Tubing and Fittings

A. Copper tubing for three-quarters (3/4) inch and one (1) inch shall be new seamless copper conforming to all the requirements A.S.T.M. Designation B-88-49 Type K soft copper. Copper tubing for one and one-half (1-1/2) inch and two (2) inch shall be Type L or better rigid copper.

B. All fittings used in connection with three-quarters (3/4) inch and one (1) inch Type K soft copper tubing shall be Mueller or Ford Quick Joint couplings (Type K copper). No other pack joint couplings will be accepted.

C. All fittings used in connection with one and one-half (1-1/2) inch and two (2) inch Type L rigid copper tubing shall be Mueller or Ford Quick joint couplings (Type K copper). No other pack joint couplings will be accepted.

D. Sweat Fittings.

1. All sweat fittings shall be brazed with a silver flow type brazing rod that shall equal or exceed phosphorus-copper brazing alloy, A.S.T.M. B260-52T AWS/A5.8 – class bcup-2; tensile strength ninety thousand (90,000) psi (six hundred twenty-one (621) MPa) self-fluxing, lead-free, manufactured by turbo-torch. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0007.2 Service Saddles

A. When a service connection is proposed on a ductile iron, cast iron, or asbestos cement main, a bronze double strap or stainless steel double bolt service saddle with neoprene gasket shall be used. Service saddles shall be AWWA I.P. thread. All service saddles shall equal or exceed those manufactured by Mueller BR2B Series; BR25, Ford Style 202B; or Jones J-979.

B. When a service is proposed on a PVC C-900 or approved main, a PVC service saddle with neoprene gasket shall be used. Service saddles shall be bronze with stainless steel double bolt straps. HINGED TYPE CLAMPS SHALL NOT BE PERMITTED. All services shall maintain a minimum of eighteen (18) inches from any other service, coupling or joint on the main. All clamps shall equal or exceed those manufactured by Mueller BR2S Series; Ford Style 202BS; or Rockwell Model No. 393. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0007.3 Corporation Stops

A. All three-quarters (3/4) inch and one (1) inch corporation stops shall equal or exceed those manufactured by Mueller B-25028, Ford FB1100Q, or approved equal.

B. All one and one-half (1-1/2) inch and two (2) inch corporation stops shall be bronze ball type valves which shall equal or exceed those manufactured by Mueller B2969, Ford FB500, or other approval equal.

C. Corporation stops of three-quarters (3/4) inch and one (1) inch shall be I.P. thread inlet. One and one-half (1-1/2) inch and two (2) inch shall be tapered c.c. or I.P. thread inlet x male iron pipe outlet. Mueller 110 and Ford Quick Joint couplings may be substituted on three-quarters (3/4) inch and one (1) inch corporation stops only (no pack-joint couplings will be accepted).

D. All corporation stops shall be installed at a forty-five (45) degree angle toward the lot to be served.

E. Corporation stops of one and one-half (1-1/2) inch and two (2) inch shall include a swing type connection consisting of two (2) ninety (90) degree brass ells and one (1) one and one-half (1-1/2) inch by two and one-half (2-1/2) inches or two (2) inch by two and one-half (2-1/2) inch brass nipple between the ninety (90) degree ells. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0007.4 Curb Stops

A. All three-quarters (3/4) inch and one (1) inch curb stops shall be bronze of the ball valve outlet type with quarter turn check. Only Mueller 110 (B25170) or Ford Quick Joint Compression (B41-333WQ) connections by iron pipe shall be accepted. They shall be installed with a brass plug to protect the threads and keep out dirt. Curb stops shall be backfilled with cinder sand, six (6) inches under and up to six (6) inches below finished grade.

1. No oriseal type curb stops are allowed.

B. All one and one-half (1-1/2) inch and two (2) inch meter valve connections shall be I.P. x I.P. ball valve type equal to or exceeding those manufactured by Mueller B-25170, Mueller 110 or Ford Quick Joint Compression Connections; Ford; B41-666WQ; or BA41-333WQ.

1. No inverted key or pack joint will be accepted for one and one-half (1-1/2) inch or two (2) inch meter valve connection.

C. Angle stop valves for three-quarters (3/4) inch shall meet or exceed those manufactured by the Mueller B-2427, or Ford BA41-333WQ or approved equal. For one (1) inch angle stop valves, use Mueller No. B24274 or Ford No. BA41-444WQ or equal.

D. Angle stop valves for one and one-half (1-1/2) inch and two (2) inch shall meet or exceed those manufactured by the Mueller B-24276; Ford BRA43-666WQ, BFA43-777WQ, Mueller 110 or Ford Quick Joint Compression Connections.

1. Flare or pack joint will not be accepted for one and one-half (1-1/2) inch and two (2) inch. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0007.5 Service Extensions and Repairs

A. All service extensions shall extend to the property line. All extension couplings shall be a sweat type, City of Flagstaff approved silver flow brazing alloy, Mueller 110, or Ford Quick Joint Compression Connection only. (No pack joint couplings will be accepted.)

B. Service extensions shall be staked vertically and horizontally in the field by a registered land surveyor.

C. A twelve (12) gauge (minimum) galvanized or copper wire with blue insulation shall be fastened to the curb stop and tied to a brick, extending above the end of the service line and placed at finished grade for future locations. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0008 Meter Requirements

In accordance with City Code, every separate building supplied with City water must have its own separate meter. The requirement to have individual water meters applies to commercial, single-family homes, townhouses, duplexes, and triplexes. A single service line and a "Master Meter" can be used for condominium, apartment or trailer court developments where two (2) or more buildings are located on the same parcel of land.

A. Water Meter Boxes.

1. The City of Flagstaff Utilities Division requires that prior to setting a meter, the contractor shall expose the curb stop, protect it from freezing, and provide one-half (1/2) CY of cinder sand within ten (10) feet of the hole for the installation of the meter box.

2. Water meter boxes shall be installed over the meter as to allow easy access to both the inlet and outlet meter couplings.

a. The curb stop shall be set a maximum of two (2) inches from the inside of the inlet side of the box and twenty (20) inches below finished grade. (See Detail No. 9-03-070.)

b. The curb stop shall be located in accordance with Detail No. 9-03-070.

3. There shall be a clear, level working area within a three (3) foot distance in all directions of the meter box with no obstructions such as fences, fire hydrants, signs, rock walls, phone/electrical pedestals, landscaping rocks, logs, bushes, or other impediment. Three (3) foot clearance shall be maintained based on full maturity of plants or trees.

4. After meter is installed and a plumber makes the customer side connection, the meter and boxes shall be backfilled with cinder sand six (6) inches beneath the bottom of the box (minimum) and up to six (6) inches beneath the finished grade around boxes (twelve (12) inches minimum).

5. Meter box locations must be out of traveled roadway, sidewalk or driveway. They may be located in landscape areas or parking lot islands. Boxes shall be set one (1) inch above finished grade to minimize flooding. Meter locations shall be easily accessible from a street or traveled way and must be located in right-of-way or easements.

6. Required private or voluntary plumbing appurtenances such as pressure reducing valves, backflow devices, curb stops (stop and wastes), shall be set with a minimum twelve (12) inch separation from the outlet coupling of meter; none of these are allowed inside the meter box.

7. Customer side shut off valves are required on all new and existing meters and shall be located just outside of the meter box, in accordance with the International Plumbing Code, Section 606.

a. The valve must have its own acceptable valve box. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0008.1 Multiple Meter Service Connections

A. U-Branches.

1. U-branches will be accepted only if there is a minimum of two (2) three-quarters (3/4) inch branches off a single one (1) inch service.

2. U-branches shall be straight line with three-quarters (3/4) inch iron pipe outlets and a minimum of thirteen and one-half (13-1/2) inch center to center separation.

3. U-branches shall meet or exceed those manufactured by the Mueller, Jones, and Ford companies, FORD UVB23-42W-13, MUELLER H-15362-13.

B. Multiple Meters: Manifolds.

1. Multiple meters in excess of two (2) on one (1) service line shall be accepted on one and one-half (1-1/2) inch and two (2) inch service connections only. The maximum number of meters allowed on one (1) service depends on the size of the service and the size of the meter. Refer to the table below:

Table 13-09-003-04
MAXIMUM NUMBER OF METERS ON ONE SERVICE
Service Size	Meter Size
	3/4 inch	1 inch	1-1/2 inch	2 inch
3/4 inch	1	0	0	0
1 inch	2	1	0	0
1-1/2 inch	4	2	1	0
2 inch	8	4	2	1

2. Each manifold of three (3) or more meters shall be constructed of copper sweat fittings (with City of Flagstaff approved silver flow brazing) with a separation of thirteen and one-half (13-1/2) inches. Each service curb stop shall have a minimum of eighteen (18) inches separation from the service connection. Each service from the service connection shall be type K soft copper.

a. Meter manifolds shall be installed in accordance with City of Flagstaff Detail No. 9-03-081.

3. All one and one-half (1-1/2) inch and two (2) inch service connections with manifolds shall have a control valve within eighteen (18) inches to twenty-four (24) inches of the manifold with cast iron valve box equal to or exceeding those manufactured by Tyler Corporation 562-A or 564-A or refer to City of Flagstaff Detail No. 9-03-081.

4. All one and one-half (1-1/2) inch and two (2) inch meter installations shall require a separate service connection per meter.

5. All meters from a manifold shall be located within the right-of-way or public utility easement. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0008.2 Compound Meters

Compound meters shall be installed in accordance with City of Flagstaff Detail No. 9-03-082 and fire service meters shall be installed in accordance with City of Flagstaff Detail No. 9-03-083. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0009 Water Main Repairs

A. Clamps. Repairs on existing water mains shall be made with stainless steel, double band, full circle repair clamps. Clamps shall equal or exceed those manufactured by JCM models 102, 132, or Smith Blair Model 227.

B. Transition Couplings. Any existing water main requiring repairs or horizontal or vertical realignments, where a transition coupling is to be used, shall require the use of transition couplings that equal or exceed those manufactured by Powerseal Model 3501 or Ford Model FC2A. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0010 Combination Air Release Valves

Combination air release valves shall be required at all in-line high points in water mains. Locate air release valves near property corners and maintain three (3) feet of clear level area. Maintain a minimum of three (3) feet horizontal separation from water meter boxes. Air release valves shall be installed in accordance with City of Flagstaff Detail No. 9-03-101 for pipes as large as twelve (12) inches in diameter, and Detail No. 9-03-100 for larger sizes. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0011 Thrust Block Design

Engineer’s design must fit the main size and soils conditions. When joint restraints are specified in lieu of, or in addition to, thrust blocks, they shall be used at all bends and fittings or where joint restraint devices are specified by the approved construction plan. Restrained joint calculations shall be prepared and submitted when necessary, keeping in mind that concrete thrust blocks are not to be considered in the calculations. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0012 Pumping Stations and Reservoirs

A. Generally, the existing City network cannot service development above certain elevations depending on the pressure zones of the main. Therefore, any development that cannot meet design minimums require pump stations or reservoirs, or both. Hydropneumatic systems are not desirable but may be allowed by the City Council where it is shown that elevated reservoirs are not practical. Decisions as to whether such systems can be added to the City network are made by the City Council, based upon recommendations of the Utilities Director, the City Engineer, and the Water Commission. If the system is outside the urban growth boundary, then approval by the Planning and Zoning Commission is required.

1. Such systems are also subject to a fee equal to the estimated amount of operation and maintenance expenses for a period of twenty (20) years. Such fee shall be agreed to by the City and Developer and paid prior to any occupancy being allowed in the development.

a. Operation and maintenance expenses shall be based on all personnel, contractual, commodities, and replacement capital costs that are estimated for the first twenty (20) years of operation. Replacement capital costs shall be based on a ten (10) year life of pumps and motors.

b. Capital with a life of greater than ten (10) years shall be depreciated based on its life expectancy.

2. The actual amount paid shall be based on the future value of the estimated amounts assuming a five percent (5%) rate of inflation, discounted back to their present value using a factor equal to the previous average six (6) month interest paid by the Arizona State Treasurer’s Office paid on the Local Government Investment Pool or other investment vehicles the City may have.

B. Pump station facilities shall be designed for peak hour demand of the peak day with provisions for fire flow. Peak day flow shall be two and one-half (2.5) times the average day demand flow.

1. Pump stations are to be designed to meet all minimum requirements of flow in the network with any one (1) of the pumps out of service. Standby power shall also be provided which is adequate to operate at peak day demands.

2. The pump building shall be weather proof, fire and vandal resistant, and architecturally harmonious with the surroundings.

3. All pump station facilities require site plan and building safety review and approval by the Utilities Division. Such review may result in additional requirements that must be satisfied.

C. Reservoir storage capacity required is to be at least two hundred fifty thousand (250,000) gallons.

D. Pump stations for residential, industrial and commercial areas shall be designed by the developer’s engineer with regard to expected water usage and fire flows. This design capacity will be reviewed and approved by the City Engineer and City Utilities Director.

1. Pump stations used to fill reservoirs shall be capable of completely filling the reservoir in twenty-four (24) hours with one (1) pump out of service while under normal demand conditions.

E. No development that is outside the City limits shall be served by City services. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0013 Wells

13-09-003-0013.1 General

Wells shall conform to the requirements of the ADEQ Engineering Design Guidelines for the Construction of Water Systems. A drilling permit from the Arizona Department of Water Resources (ADWR) shall be obtained. A design report of system capabilities and production influence will be required. This section of the standards covers the basics in well design. A more detailed description of well requirements can be found in AWWA-A100. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0013.2 Construction Materials

A. The acceptable materials for well casings are:

1. Single-ply carbon steel conforming to ANSI/AWWA C305, API Specification.

2. Single-ply high strength, low alloy steel conforming to ASTM A714.

3. Single-ply stainless steel conforming to ASTM A409.

B. Acceptable joint types for casing materials are welded or threaded AWWA C206. All screens and fittings shall be stainless steel including twenty (20) foot blank pump chambers. Spacers shall be of the same material as the blank casing and well screen. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0013.3 Design Considerations

A. Minimum design considerations by the Utilities Division for well facilities are as follows:

1. A six (6) foot tall chain link perimeter fence with locked entrance enclosing the compound.

a. The fencing shall be compatible with the surrounding environment, including landscaping.

2. The facility entrance shall have a twelve (12) foot wide double drive access gate with at least twelve (12) feet clear space.

3. The station shall have a paved access road at least twelve (12) feet wide with a maximum slope not to exceed twelve percent (12%).

a. A forty-five (45) foot radius turnaround shall be provided if the access road exceeds fifty (50) feet in length.

4. The interior of the compound shall be surfaced with four (4) inches of asphaltic cement pavement.

5. Service vehicle access to major station components shall be incorporated in the station design.

6. Down cast facility lighting, both wall mounts and pole mounts shall be provided with at least one (1) photocell operated light.

a. The light switch shall be located next to the access gate in the interior of the compound.

b. Lights shall be dark sky compliant.

7. Heavy equipment access for a well workover rig shall be incorporated in the site layout.

8. The site shall be graded to provide adequate drainage away from structures.

9. On-site chlorine equipment (as required in consultation with the Utilities Division).

10. Well casing.

11. Screen.

12. Column pipe.

13. Discharge piping plus pitless adapter.

14. Check valve on discharge line.

15. Hose bib type sampling tap on system side of check valve.

16. Well vent.

17. Pump plus motor.

18. Sanitary well seal air and water tight.

19. Pump base concrete slab.

20. Air release valve between the pump and check valve.

21. After placement of the pump, wells shall be disinfected in accordance with ADEQ Engineering Bulletin No. 8, Disinfection of Water Systems.

22. Air and sand removal shall be included in the design of the well house.

B. The pump base concrete slab shall extend a minimum of six (6) feet from the center of the well, be six (6) inches thick and slope away from the well head a minimum of one-quarter (1/4) inch per foot. The site shall drain away from the well and be protected against erosion to prevent surface runoff from entering the well. The screen length, aperture size and construction shall be in accordance with AWWA A100. The well shall be sealed and protected from the entry of contaminants or water from any source other than the selected aquifers. Sealing of the well shall consist of grouting the following:

1. The annular space between the casing and bore hole to a minimum depth required to exclude pollution, or five hundred (500) feet, whichever is greater.

2. All zones containing water of undesirable quality or zones to be protected but excluded from final well completion.

a. These areas shall be grouted from at least five (5) feet above the zone to at least five (5) feet below the zone.

3. All passages or formations that pollutants may enter such as outcrops, old wells, excavation, limestone, sandstone or fractured rocks.

a. Joints between screen sections and blank casing spacers shall be welded or threaded and be water tight, straight and as strong as the screen.

b. The top of the well shall be constructed so that no foreign matter or surface water can enter during or after construction.

c. On completion of the well, the well shall be temporarily capped to prevent surface pollutants from entering until pumping equipment is installed.

C. Below ground pits to house the pumping equipment are prohibited.

D. Wells shall be constructed round, plumb, and true to line within the following tolerances:

1. The alignment must be satisfactory for the successful installation and operation of the permanent pumping equipment.

E. Wells shall be tested for alignment and plumb in accordance with AWWA A100, Section 8.

F. New wells shall be performance tested to acquire water samples and to determine well capacity, draw down and production on a long-term basis. Testing methods shall be in accordance with AWWA A100, Section 10.

G. All facilities require site plan and building safety review and approval by the Utilities Division. Such review will result in additional design requirements that must be satisfied. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0013.4 Abandoned Wells

A well abandonment plan and notice of intent to abandon must be submitted and approved by the ADWR. See State statutes regarding abandonment for State requirement. Abandoned wells and test wells shall be sealed by an ADWR licensed well driller to restore the controlling geological conditions that existed before the well was constructed. An acceptable alternative is to completely fill the well with concrete. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0014 Water Storage Facilities

13-09-003-0014.1 General

A. Water storage facilities shall conform to the requirements of the ADEQ Engineering Design Guidelines for the Construction of Water Systems. Reservoir capacity for residential, industrial, and commercial areas shall be designed by the developer’s engineer with regard to expected water usage and fire flows.

B. The overall objectives of finished water storage are to:

1. Assist in meeting peak flow requirements.

2. Equalize system pressures.

3. Provide emergency water supply in case of component failure.

4. Permit high service pumps at treatment plants to operate at a relatively uniform rate.

5. Provide for fire flows. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0014.2 Construction Materials

The materials and designs used for finished water storage units shall provide stability and durability as well as protect the quality of the water. Steel structures shall follow the current AWWA Standard D100 concerning steel tanks, standpipes, reservoirs and elevated tanks. The materials and design are subject to Utilities Division approval. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0014.3 Storage Capacity Sizing

A. The Utilities Department requires that storage facilities be sized to accommodate the average daily flow plus fire flow storage requirements. The average day demands are established using the criteria set forth in these regulations.

1. Water storage sizing shall be based on net capacity.

a. Net capacity is less than gross capacity due to the unusable volume of the storage facility.

B. The storage design capacity will be reviewed and approved by the City Engineer and City Utilities Director.

C. Minimum reservoir storage capacity required is to be at least two hundred fifty thousand (250,000) gallons. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0014.4 Design Considerations

A. The minimum design considerations for water storage facilities are as follows:

1. A six (6) foot tall masonry perimeter wall or fencing with locked entrance enclosing the compound. The wall shall be compatible with the surrounding environment, including landscaping.

2. The facility entrance shall have a panel style, dual swing access gate with at least sixteen (16) feet clear space.

3. The station shall have a paved access road at least twelve (12) feet wide with a maximum slope not to exceed twelve percent (12%).

4. The interior of the compound shall be surfaced with a four (4) inch compacted aggregate base including a weed barrier.

5. Service vehicle access to major station components shall be incorporated in the station design.

6. Down cast facility lighting, both wall mounts and pole mounts, shall be provided with at least one (1) photocell-operated light. The light switch shall be located next to the access gate in the interior of the compound. Lights shall be dark sky compliant.

7. For nonelevated storage, a backup power supply capable of operating the pump station for eight (8) hours during power outage. Specific criteria for backup generation type and capacity shall be given during design process.

8. The site shall be graded to provide adequate drainage away from structures.

9. On-site chlorine generation equipment (if required).

10. Storage tank with acceptable interior and exterior coating systems for potable water.

11. Concrete foundation ring.

12. Inside and outside steel ladders.

13. Outside ladder safety cage with locking security gate at base.

14. Water level indicator.

15. Tank vent housing.

16. Two (2) separate thirty-six (36) inch, square-hinged roof access openings (one (1) with inside and outside ladder).

17. Cathodic protection system as required in consultation with the Utilities Division.

18. Overflow pipe and splash pad.

19. Hinged shell manhole.

20. Altitude valve, isolation valves, bypass line and vault.

21. Tank discharge line.

22. Tank fill line.

23. Booster station suction line (where applicable).

24. Tank drain.

25. Disinfection system as required in consultation with the Utilities Division.

26. Electrical and SCADA/telemetry system.

27. Pressure transmitter for telemetry.

28. A clear area around reservoir to allow vehicle passage. Clearance width shall be sized in consultation with the Utilities Division.

All facilities require site plan and building safety review and approval by City of Flagstaff. Such review may result in additional requirements that must be satisfied. (Ord. 2017-22, Rep&ReEn, 07/05/2017)

13-09-003-0015 Water Systems Not a Part of City Systems

A. No development that is outside the City limits shall be served by City services.

B. Any development, which does not tie to the City water system, is required to meet the approval of all applicable agencies. Such approval, to be obtained by the developer, is in addition to City and Health Department approvals required. All subdivisions and minor land divisions are required to be served by public water, sewer, and roads.

C. Private fire mains shall not be allowed. Existing private fire mains shall be maintained as required and regulated by the City Fire Department. No private water lines may cross into or over the public utility easement, right-of-way, or private property owned by others. (Ord. 2017-22, Rep&ReEn, 07/05/2017)