Appendix C - Standard Specifications for Water Main Construction
EFFECTIVE: JANUARY 2006
CHAPTER 1 - GENERAL REQUIREMENTS
The Standard Specifications for Water Mains as set forth herein ("Specifications") are promulgated by the following: Arrowhead Metropolitan District, Bachelor Gulch Metropolitan District, Beaver Creek Metropolitan District, Berry Creek Metropolitan District, Cordillera Metropolitan District, Eagle River Water & Sanitation District, Eagle-Vail Metropolitan District, Edwards Metropolitan District, Town of Avon, Traer Creek Metropolitan District (Village at Avon), and Upper Eagle Regional Water Authority ("District"). The interpretation and enforcement of said Specifications is hereby delegated to the Regulations Administrator of the Eagle River Water & Sanitation District.
1.02 EFFECTIVE DATE OF SPECIFICATIONS
The Specifications shall become effective immediately upon formal adoption by the District and shall supersede all former specifications for water main construction.
1.03 REVISIONS, AMENDMENTS, OR ADDITIONS
The Specifications may be revised and/or amended. Such revisions, amendments, and additions shall be binding and in full force immediately upon formal adoption by the District.
As used in the Specifications, unless the context shall otherwise require, the words defined in this paragraph shall have the following meanings:
A. Applicant: Any person, association, corporation, entity, or governmental agency desiring water services for premises under its control.
B. Applicant Representative: The designated representative of the Applicant acting with the scope of the particular duties entrusted to the individual.
C. Connection: In the context of these Specifications, a service line shall only exist from the tap on the main to the curb stop valve, which shall be located on the property line.
D. Contractor: In the context of these Specifications, a person or persons, association, corporation, or entity employed by an Applicant for the purpose of installing water system extensions or replacements.
E. Defective: Work that is unsatisfactory, faulty, or deficient, or does not meet the requirements of any inspection, test, or approval referred to in the Specifications, or has been damaged prior to the Water Entities' approval.
F. Distribution System: Water mains together with all appurtenances including valves, fire hydrants, taps, meters, service pipes from main to curb stop, or property line/easement (whichever is closer to the main), and associated materials, property, easements, and equipment distributing water to customers.
G. District: The following Water Entities: Arrowhead Metropolitan District, Bachelor Gulch Metropolitan District, Beaver Creek Metropolitan District, Berry Creek Metropolitan District, Cordillera Metropolitan District, Eagle River Water & Sanitation District, Eagle-Vail Metropolitan District, Edwards Metropolitan District, Town of Avon, Traer Creek Metropolitan District (Village at Avon), and Upper Eagle Regional Water Authority.
H. District Engineer: Authorized representatives acting within the scope of the particular duties entrusted to them.
I. District Inspector: Authorized representatives acting within the scope of the particular duties entrusted to them.
J. District Main: Water mains eight inches (8") or greater which have been formally accepted by the District.
K. Electronic Drawing File: AutoCAD or equivalent computer design software digital submission meeting the design requirements of the District.
L. Main Extension: Extension to the existing water distribution system located within the District.
M. Regulations Administrator: The authorized representative of the District who acts within the scope of the particular duties entrusted to that position.
N. Service Line: Any pipe, line, or conduit used or to be used to provide water service from a water main to a curb stop located at the property line. A water service line shall be owned and maintained by the District from the tap on the District water main to the property line, edge of easement, or curb stop, whichever is closer to the water main.
O. Shop Drawings: All drawings, diagrams, illustrations, brochures, and other data which are specifically prepared by contractor, subcontractor, manufacturer, fabricator, supplier, or distributor to illustrate some portion of the work and submitted by the foregoing to illustrate material or equipment for some portion of the work.
P. Variance: A "variance" is the written authorization from the District or District staff to act in a manner not in strict compliance with District Standard Specifications for Water Mains or policies. A variance may be granted at the sole discretion of the District on the basis of undue hardship, or otherwise, not self-imposed.
CHAPTER 2 - MAIN EXTENSIONS
2.01 RESPONSIBILITY FOR MAIN EXTENSIONS
All main extensions within the District or total service areas shall be made at the expense of the Developer or Applicant. The District encourages all contractors to videotape any potential areas affected by any construction prior to construction so as to avoid any potential conflict that may arise during or after construction.
2.02 APPLICATION PROCEDURE
All inquiries, applications and submission of plans for main extensions shall be initiated through the District's office at 846 Forest Road, Vail, Colorado 81657, (970/476-7480). The initial submission shall consist of two (2) sets of drawings.
The engineering design and water plan portions of the extension applications shall include the following:
An overall or master plan showing the area to be developed and any adjoining proposed developments by the Applicant. The plans shall include:
1. Points of connection to existing facilities with specific District attribute nomenclature.
2. Size of water mains to be installed.
3. Locations of water mains to be installed.
4. Special features such as pressure regulating valves, blowoff valves, relief valves, booster pumps, tank sizes, capacities, etc.
5. Materials list.
The Applicant shall submit final plans prepared and signed by a Professional Engineer, registered in the State of Colorado, for review by the District.
The District will require attendance of applicant(s) or representative at the initial review/submittal meeting. The District shall check all submittals for conformance with the Specifications and other applicable rules and regulations and either approve the submittal or return it to the Applicant for correction. The Applicant is responsible for complete compliance with the Standard Specifications for Water Mains. The Specifications will take precedence over the District's plan review. The District is not responsible for omissions that may occur during its plan review process.
All final plans must be presented for approval to the Fire Department having jurisdiction prior to submittal to the District. Submitted plans must have a letter of approval from the appropriate fire department.
2.03 SUBMISSION REQUIREMENTS FOR SYSTEM EXTENSIONS
Detailed plans for main extensions shall be prepared for approval in conjunction with the submittal to the District. All plans submitted shall be in strict compliance with the Specifications contained herein AND SHALL MEET SPECIAL CONDITIONS THAT MAY BE REASONABLY REQUIRED.
Construction Plan Approval will not be granted without inclusion into all applicable District boundaries, issuance of an Ability to Serve letter or the determination that the letter is not required, resolution of all water rights dedication requirements, and payment of any treated water storage. All fees must be paid prior to connection to the District's system.
The design and installation of all facilities shall ensure development of an integrated distribution system. No work shall commence on any facilities until the plans for construction are approved in writing by the District and three (3) copies of the approved plans are returned to the Regulations Administrator's office.
When a main is to be installed outside of the public street right-of-way, within an easement or right-of-way dedicated for main installations, the Applicant shall be responsible for providing restoration and landscaping adequate to prevent erosion caused by surface run-off. Landscaping and restoration construction shall be designed in such a manner that minimum future maintenance will be required.
Proposed mains to be installed within a dedicated line easement or right-of-way may require plan and profile drawings to be prepared by the Applicant's engineer and approved by the District.
All final plans shall contain, but are not limited to, the following information:
A. Plan View Containing Or Showing:
1. Boundary lines including recorded plat information showing location and dimensions of dedicated roads, right-of-ways, and easements.
2. Lots and blocks.
3. All existing and proposed improvements.
4. All existing or proposed utilities that may conflict with water installations. Submittals shall include size, type, and locations.
5. The proposed alignment and size of the lines will include the location of all proposed facilities such as valves, fire hydrants, fittings, etc.
B. Additionally, All Plans Shall:
1. Be made from actual field surveys and shall reference land corners or other official survey control points and be of sufficient accuracy so that the facilities can be accurately staked for installation and can be readily located after installation for maintenance and tapping and control.
2. Conform to a scale of one-inch (1") equals 100-feet (100') on 24-inch by 36-inch material. Larger scales shall be used when necessary to adequately show specific details of mains, connections, and other installations.
3. Show sufficient adjacent area to give the relation of new facilities to existing facilities. Existing facilities will be identified on the plans with District nomenclature.
4. Show profile information depicting proposed lines and grades.
Variances to these specifications may be granted at the sole discretion of the District on the basis of undue hardship, or otherwise, not self-imposed.
2.04 CONSTRUCTION PROCEDURE
Following final approval of the plan(s) by the District, the Applicant may proceed with construction. In addition to all construction requirements contained in other portions of the Specifications, the Applicant and his Contractor shall complete the following:
A. Three (3) sets of plans, one wet stamped, shall be submitted to the District for construction inspection purposes. The District also requires a digital submittal of the approved plans in District-specified format.
B. A mandatory pre-construction meeting shall be held on-site 48 hours prior to any excavation. Participants may include, but are not limited to, the following: representatives of the Contractor, Excavator, Engineer, Applicant, and District.
C. In the event that said construction does not commence within twelve (12) months of the approval date, the plans must be resubmitted for review and approval. If construction on the main installation is halted for more than twelve (12) months, plans must be resubmitted for review and approval prior to commencement. Resubmitted plans must adhere to the most recently updated specifications.
D. The Applicant shall secure and pay for all licenses and permits required for the main line extension.
E. Adequate provisions for notification of customers who may suffer interruptions in service must be made. Interruptions shall be kept to a minimum. All affected customers shall be notified, in writing, at least 48 hours in advance of construction, and on any scheduled interruption of service.
F. Mains shall be disinfected and tested in accordance with the Specifications set forth and referenced herein.
G. No service line "dry taps" are allowed. Service line "wet taps" will only be allowed after the line has passed the entire District required inspections and tests. The main line Contractor shall perform "wet taps" on all newly constructed lines.
H. Water taps shall be made above the spring line of pipe. Spring line is defined as the horizontal mid-line of any main line.
I. All water taps on new main line extensions shall be made by the Contractor and inspected by the District Inspector.
A. New installation, replacement, or repair of any existing facilities in the District's distribution system shall be inspected and approved by a District Inspector. The District Inspector shall ensure that the provisions of the Specifications are carefully complied with, particularly in regard to the quality of workmanship and materials. Problems that may require field judgment, in lieu of strict interpretation of the Specifications, shall be resolved by the Applicant to the satisfaction of the District Inspector.
All work shall be performed in accordance with accepted workmanship practices and the Specifications set forth and referenced herein. Any work not accepted by the District Inspector shall be redone until compliance with District Standard Specifications is achieved.
All appropriate permits and approved water plans shall be kept on the job site during construction.
The District Inspector shall not supervise, set out work, or give line or grade stakes. A Representative of the Applicant shall be at the project site at all times that construction is in progress. The District Inspector shall discuss the work with the Applicant or Applicant's Representative only. Only the Applicant will give instructions to the project workers. If, at any time during construction, it is found that the Applicant's Representative is not on the project site, the District Inspector may stop work until the Applicant's Representative is present at the project.
B. All material used shall be subject to the inspection and approval of the District Inspector at all times. The District Inspector has the right to perform any testing deemed necessary to ensure compliance of the material with said Specifications. Failure or neglect on the part of the District Inspector to condemn or reject inferior materials, or work, shall not be construed to imply the District's acceptance should their inferiority become evident at any time prior to completion of a TWO-YEAR (2) warranty period from the date of "Construction Acceptance." Materials rejected by the District Inspector shall be immediately removed from the job site.
After receipt of approved plans from the District, the Applicant shall give at least 48 hours notice to the District, telephone number 970/476-7480, prior to starting construction. No construction shall commence sooner than 48 hours after receipt of approved plans.
2.06 PERFORMANCE AGREEMENT AND CONVEYANCE AGREEMENT
The Applicant shall furnish to the District a guarantee for the satisfactory repair or replacement where required, or the cost thereof, of all work, material, services and equipment which becomes defective as a result of faulty material, faulty installation, or improper handling of material and equipment installed by the Contractor. Such guarantee shall be for a period of TWO (2) YEARS from the date of Construction Acceptance by the District. Any repair made on any main will require an additional warranty period consisting of one (1) year after the date of repair approval by District personnel. Each repair will constitute an additional one (1) year warranty period.
The District shall provide a "Bill of Sale" form to the Applicant. The Applicant shall complete the form, attach the required exhibit and return it to the District for final approval.
A copy of the final approved form may be sent to the Applicant.
If paving does not occur prior to the end of the 2-year warranty period, the warranty period will be extended. The final grade and paving inspection must occur prior to the expiration of the required warranty period. The District will perform the final grade and paving inspection within ten (10) days of notification by the developer. A representative from the developer must be present during the inspection.
Warranty period shall not expire until the final inspection has occurred and the Drawings of Record and recorded easement documents have been received and approved by the District.
2.07 SPECIAL CONDITIONS
When applying for a main extension, special conditions that involve another agency, such as crossing a railroad or highway, may exist. All conditions of the appropriate agency must be satisfied. All designs, drawings and calculations submitted to another agency shall also be submitted to the District for approval. Should a conflict in the plans and specifications occur between the District and the other agency, the more stringent plans and specifications yielding a higher quality product shall prevail. A District Representative shall determine this. A traffic control plan, approved by the appropriate agency, shall be submitted to the District.
2.08 DRAWINGS OF RECORD
The Applicant will be required to submit a complete set of "field verified" Drawings of Record depicting the actual alignment of the main line extension complete with the locations of all valves, fire hydrants, vaults, and related appurtenances including service lines and curb stop locations. Additionally, curb stop valves shall be located by a minimum of three (3) "swing ties" off permanent landmarks (does not include property pins) per valve. The District requires submitted drawings of record to be accurate and complete. The District will verify general conditions as constructed. The District will not correct drawings of record. This information shall be required as part of the drawings of record submittal. All easements related to main line extensions shall be contained within the electronic submittal. The drawings of record information shall be submitted on a set of the approved construction drawings as well as in digital form using the District's computer format (AutoCAD 14 or newer) and nomenclature. See standard drawings for additional details.
2.09 MAIN LINE TESTING
Immediately after main line installation, the Contractor will conduct a High Chlorine Test, a Low Chlorine Test, a Bacteriological Test, and then a pressure test of the main line to ensure that the line is not leaking. No more than 1,000 feet of line shall be tested at one time. If it is discovered that the main line is leaking, it will be the responsibility of the Applicant to make all necessary repairs and retest the main line. No tap shall be made on to the main line until the main line has successfully passed all tests. The District shall witness the testing.
The specific tests required by the District are listed on the "Water System Acceptance Procedure Form". The form is displayed on page 56 of these Standard Specifications for Water Lines.
Before the end of the TWO-YEAR (2) warranty period, the District will conduct a sounding, an acoustical method of leak detection, of the main line at working pressure to ensure that the main line is not leaking. The cost of this testing will be borne by the District. If it is discovered that the main line is leaking, it will be the responsibility of the Applicant to make all necessary repairs and retest the main line and services to the curb stops. The District shall witness the re-testing.
CHAPTER 3 - DISTRIBUTION SYSTEM DESIGN AND LAYOUT
3.01 OVERALL UTILITY PLAN
The District will require an Overall Utility Site Plan of the project to be submitted indicating all utilities and their proposed locations for review prior to Construction Plan Approval. All plans submitted shall include a geotechnical report if requested by the District. Corrosive soils may require upgrade to corrosive-resistant materials and shall be addressed by the design engineer.
3.02 DETERMINATION OF CORROSIVE SOILS
Prior to Construction Plan Approval, applicants must perform and provide the results of soils corrosivity tests within the proposed project area or confirmation from a geotechnical engineer that corrosive soils are not known to exist in the project area. Soils shall be sampled at a frequency and locations recommended by geotechnical engineer to adequately assess the risk of corrosive soils. If soils are determined to be corrosive by a geotechnical engineer, the applicant must include an engineered mitigation plan with their construction plan submittal.
3.03 SIZING DISTRIBUTION MAINS
All mains shall be sized large enough to provide for domestic, irrigation, and fire protection flows to the area requesting service. The minimum size of all District mains shall be eight inches (8").
The District reserves the right to oversize mains to provide service for projected future needs. The additional cost for the oversize may be negotiated between the District and the Applicant.
3.04 FIRE PROTECTION
A. The number and location of fire hydrants in a given area must be approved by the appropriate governmental agency.
Fire hydrant branch lines shall be set at right angles to street mains. The fire hydrant shall be set at the end of the branch line and shall face the direction as dictated per local fire authority. No horizontal bends or offsets shall be used in installing fire hydrant branch lines unless approved by the District. Under no circumstances shall any size or manner of tap be made on a fire hydrant branch line between the hydrant and hydrant valve. The maximum length of 6-inch main line shall not exceed 50 feet. All fire hydrant valves shall be attached to the tee off of the main line. A fire hydrant shall be installed at the end of all dead end water mains. The Applicant shall install an approved fire hydrant marker on all fire hydrants.
The Applicant shall perform all fire hydrant "flow tests". Results of flow tests shall be provided to the District and to the local fire authority. All costs associated with the "flow test" shall be borne by the Applicant. The District shall witness and oversee the "flow test" in conjunction with other appropriate governmental agencies.
3.05 DISTRIBUTION REGULATING INSTALLATIONS
Regulating installations are required to control pressure, provide pressure relief, and separate pump and gravity zones throughout the distribution system. When main extension plans are submitted for review, the need for regulating installations must be approved by the District as determined by existing and proposed pressure zones, booster pump areas and the existing distribution system piping. Presently, regulating installations shall be categorized as follows:
1. Pressure Regulating Station
2. Pressure Relief Station
3. Check Valve Station
Location and pressure settings of main line pressure regulating devices will be reviewed by the District on a case-by-case basis.
All regulating installations will be reviewed and approved by the District and installed by the Applicant. At all high points in the main line distribution system, a combination air vacuum and air release valve shall be installed in a minimum five foot (5') diameter manhole.
3.06 PUMPING FACILITIES
All proposed booster-pumping facilities shall be considered as a special feature and dealt with on an individual case basis. The size, location, and type of the booster pumping facilities shall be reviewed and approved by the District. Every effort shall be made to provide facilities, which are consistent with the District's existing booster pump stations. See Chapters 8 and 9 for minimum requirements.
3.07 STORAGE FACILITIES
Water storage reservoirs or tanks are required throughout the distribution system to maintain adequate supply during peak demand periods and to provide storage for emergency and fire flow requirements. Storage reservoirs may also be required adjacent to and on the suction side of pumping facilities. All main line installations to storage tanks shall be required to have a fire hydrant adjacent to the tank to accommodate testing and inspection purposes. The size, location, and type of storage reservoirs shall be reviewed and approved by the District.
All proposed storage tanks shall be considered a special feature and will be dealt with on an individual case basis. All proposed storage tank facilities shall be submitted and approved by the District prior to construction of these facilities.
Depending on the type of construction proposed for the water storage tank, the tank should, at a minimum, be designed in accordance with AWWA specifications D100, D103, D110, or D115. For tank construction not covered by the above listed AWWA standards such as post-tensioned concrete, the design should, at a minimum, meet applicable industry standards and specifications.
Cathodic protection shall be provided for all steel water tanks and the interior and exterior steel components in steel or concrete water tanks.
All vents shall be adequately screened and secured. All drains and overflow lines shall have a flapper valve or a tide-flex check valve.
Locking hatch with intrusion alarm is required. The intrusion alarm must be capable of transmitting a digital output (open/close contact switch) signal to the Avon Drinking Water Facility (ADWF) computer. Locking hatch must be rated for corrosive environment.
3.08 TREATED WATER STORAGE DEDICATION
Owners of property upon which new development or re-development is proposed, which is located within the Authority's service area, and which will require an increase in water use or new water use not allowed by existing taps or zoning to provide treated water storage adequate to meet the needs of the owner's proposed development, or, at the option of the Authority, shall pay cash in lieu of new treated water storage.
The amount of water storage required shall be equal to the combined volumes of water calculated to meet the need for Equalization Storage, Emergency Storage, and Fire Flow Storage for the development. Equalization Storage shall be equal to 25 percent (%) of Average Daily Demand (ADD), Emergency Storage shall be equal to 100 percent (%) of ADD, and Fire Flow Storage shall be calculated based upon the greatest fire flow required by the fire department within the service area of the tank. ADD shall be defined as 350 gallons per Single Family Equivalent (SFE).
For proposed developments that are required to provide treated water storage that are within the service area of an existing Authority tank having excess capacity (as determined by the Authority) to serve the proposed development, or where the Authority is planning to construct new regional facilities with the capacity to serve the proposed development, the owner may pay cash in lieu of treated water storage to the Authority. If the Authority agrees to accept cash in lieu of treated water storage, the amount of the fee shall be $1.75 times the volume (gallons) of treated water storage calculated to meet the needs of the development. The volume shall be calculated as follows:
ADD/SFE x 0.25
|Emergency Storage||=||ADD/SFE||=||350 gallons/SFE|
|Fire Flow Storage||=||ADD/SFE x 0.75||=||263 gallons/SFE|
|Total Storage per SFE||=||700 gallons/SFE|
For proposed developments that the Authority determines cannot be served by an existing treated water storage facility, the property owner shall provide a water storage tank or tanks and the land therefore. Tanks shall be sized as follows:
|Equalization Storage/SFE||=||ADD/SFE x 0.25||=||87 gallons/SFE|
|Emergency Storage/SFE||=||ADD/SFE||=||350 gallons/SFE|
|Fire Flow Storage||=||Minimum 180,000 gallons (= 1,500 gpm x 2 hours fire flow), sized to provide at least the volume needed to deliver the greatest fire flow requirement within the zone as recommended by the presiding fire department. For example: a fire flow requirement of 3,500 gpm for 3 hours = 630,000 gallons.
If the proposed development is to be served by a new water storage tank, the owner shall submit tank design plans to the Authority Construction Review Team and obtain approval prior to starting construction. Treated water storage shall be placed in service prior to the delivery of water service to the development by the Authority. If the Authority approves the payment of cash in lieu of providing treated water storage, payment shall be made in full to the Authority prior to construction plan approval for the development infrastructure.
In summary, the treated water storage requirement is equal to 700 gallons or $1,225 per Single Family Equivalent (SFE).
3.09 LAYOUT OF THE DISTRIBUTION SYSTEM
A. Easement Width Requirements for Main Installations
All mains shall be installed in dedicated public street right-of-ways or dedicated water line easements. The standard easement width for all main lines shall be a minimum of 20 feet and depth of cover shall be 7 feet to 9.5 feet. The main shall be generally centered within the easement. This vertical measurement shall be from finished grade to the top of the bedding. The easement width shall be based on a one-to-one (1:1) slope with a three-foot (3') base rounded up to the nearest five-foot (5') increment.
B. Fire Hydrants
Fire hydrant depths shall be 7-feet to 9.5-feet.
All fire hydrants will be installed within dedicated streets, right-of-ways, or easements as herein above defined.
Fire hydrants shall be installed at locations approved by the Fire Department, the District or the appropriate governmental agency, and at the end of all dead-end line extensions.
C. Minimum Size
The minimum size of all District mains shall be eight inches (8") in diameter. All water service line shall be a minimum of one-inch (1") in diameter.
D. Bonded Joints and Tracer Wire
A Number 4 conductor and Cad-Welds (charge size CA 45) or the manufacturers' supplied strap shall be used to bond each joint and fitting. In addition, a ten-gauge (10) insulated tracer wire shall be required on all main line installations.
E. Line Valves
Line valves are required at a minimum of one (1) every 1,000 feet. Additional valves may be required to further isolate the system at all branches and tees. Valves are required on all crosses and tees.
F. Thrust Blocks
Special station numbers, i.e., fire hydrants, valves, bends, etc., on submitted construction drawings shall identify all thrust blocks.
All thrust blocks shall be formed with a minimum of 3/8-inch plywood or District approved equivalent. Forming shall take place on the sides of the thrust block. The rear area of the block shall be placed against undisturbed soil. See Concrete Thrust Block detail.
All thrust blocks shall be inspected and approved by the District Inspector prior to backfill.
Megalugs shall be used in conjunction with all thrust blocks installations. Thrust blocks may be eliminated if megalugs have been engineered.
G. Groundwater Barriers
Groundwater barriers may be required in all areas where groundwater is encountered based on the Engineer's recommendation.
H. Depth of Bury
The depth of cover for water lines shall be a minimum of seven feet (7') and a maximum of nine and 1/2 feet (9'5") from finish grade to the top of the water line. Profiles of water lines will be reviewed on a case-by-case basis for optimum design.
I. Location Tape
All lines connected to District mains in any way shall be marked with the appropriate tape to be placed twenty-four (24) inches above the highest point of said lines.
J. Abandonment of Existing Water Mains and Valves
All abandoned water mains shall be appropriately terminated at the main. The Contractor shall maintain the existing waterline until such time as the new waterline has been pressure tested, chlorinated, bacteria tested and approved. Valve stacks on abandoned lines shall be completely removed and backfilled.
K. Pipe Deflections/Bends
All plans must reflect deflections, elbows, bends, and their degree of angle. The use of vertical bends is discouraged. Megalugs shall be used in all change of direction fittings. The use of 90-degree elbows is preferable to the use of two 45-degree elbows. The use of 45-degree elbows will be considered on a case-by-case basis.
L. Tees/Wet Taps
All tee/wet taps shall be clearly indicated on the plans to reflect installation method to be used. Each leg of a tee or cross will require the installation of a valve. Three-inch (3") or larger connections must be made with cut in tees (wet taps may be considered on a case-by-case basis). Three-inch (3") or less connections will be made with wet taps.
M. Pressure Reducing Valve Vaults
All pressure reducing valve vaults shall be designed with location out of the roadway right-of-way within the utility easement.
N. Main Insulation Requirements
For every foot of cover that is out of compliance within a main line installation, the District will require the installation of 1-inch of insulation.
O. Air Vac Vaults
Air vac vaults shall be required at all high points of the distribution system.
P. Minimum Distance from Structures
All main line extensions shall be installed at a minimum distance of ten feet (10') from all structures or at a one-to-one foot (1.0' to 1.0') ratio from any structure, whichever is greater. The minimum distance may be reduced if the footers of the structures are lowered to a depth similar to that of the water line. Encroachments into easements are discouraged and shall only be allowed by written authorization from the District.
3.10 DESIGN OPERATION PRESSURE
The design operation pressure for District shall be a maximum of 250 psi. The minimum operating pressure at any tap shall be 60 psi; the maximum operating pressure shall not exceed 190 psi.
CHAPTER 4 - MATERIAL SPECIFICATIONS
4.01 MATERIALS AND TESTING
All materials shall conform to the District's Specifications.
All materials utilized shall be new and undamaged. Everything necessary to complete all installations shall be in accordance with the Specifications and all installations shall be completed as fully operable functioning parts of the District's System.
Acceptance of materials, or the waiving of inspection thereof, shall in no way relieve the Applicant of the responsibility for furnishing materials meeting the requirements of the Specifications.
4.02 PIPE AND FITTINGS
All pipe and fittings used in the District's System shall meet or exceed the latest AWWA Specifications and follow the guideline lines set forth below:
A. Ductile Iron Pipe: AWWA C151, class 52, working pressure 350 psi, with cement-mortar lining, AWWA C104. Bituminous outside coating one mil. thick. Pipe joints shall be either restrained joint or push-on type utilizing rubber ring gasket, AWWA C111. Restrained joint systems must receive written approval from the District.
B. Steel Pipe: All steel pipe and fittings shall be fabricated in accordance with AWWA C200 Standard for Steel Water Pipe-eight inches (8") and larger-and AWWA M-11 Steel Pipe Manual. Working pressure shall be 350 psi.
All material used shall be acceptable under ASTM A283 Standard Specification for Low and Intermediate Tensile Strength Carbon Steel Plates of Structural Quality, or ASTM A36 Standard Specifications for Structural Steel.
For mill-type pipe, all material used shall be acceptable under ASTM A53 Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated Welded and Seamless.
All fittings shall be fabricated from tested pipe and dye checked in accordance with AWWA C208.
All steel pipe and fittings shall be prepared, primed, lined, coated, painted, or wrapped as hereinafter specified: Exterior Surfaces: Tape coating system conforming to AWWA C209 and C214. Interior Surfaces: Cement-mortar lining conforming to AWWA C205.
C. HDPE Pipe: With recommendation from the engineer, and approval by the District, this pipe may be used as an alternative in those applications where "hot soils" are determined to be found.
D. Fittings: Fittings shall be made of ductile iron and in accordance with the requirements of AWWA C153, pressure rating 350 psi. Mechanical joints shall conform to AWWA C111. Bolts and nuts shall be low-alloy steel. All fittings shall be cement-mortar lined, AWWA C104. Bituminous outside coating shall be a minimum of one-mil. (1) thick. Fittings must meet or exceed pipe classification.
E. Joint Restraint Devices: Joint restraint devices shall be made of ductile iron. Twist-off nuts, sized the same as the tee-head bolts, shall be used to ensure proper actuating of restraining devices. Joint restraint devices shall be EBAA Iron, Inc., Megalug Series 1100 or 1700 or Uni-Flange Corp. Series 1400 for new pipe restraint and EBAA Iron Sales, Megalug Series 1100SD or 1100HD or Uni-Flange UFR1300-C or UFR1390-C for existing pipe restraint, or accepted equal. Field locked gaskets are not allowed to be installed.
F. Solid Sleeves: Solid sleeves shall be made of ductile iron, mechanical joint, long body. Sleeves shall have a minimum pressure rating of 350 psi. A solid sleeve is to be used to join two pieces of pipe of the same diameter where no bell and spigot are present. A "wedding band" is to be inserted between the two pipes inside of the solid sleeve. No other couplings will be accepted.
G. Tapping Sleeves: Wet taps shall only be made with the use of a tapping sleeve. The District will allow epoxy-coated Mueller H304 (250 psi working pressure) or equivalent. No tapping sleeves will be allowed for any application with a working pressure of 150 psi or higher. For those applications where working pressure exceeds 150 psi, the District will require the use of a tee.
The valves shall be the same size as the main.
A. Gate Valves
Gate valves shall be Mueller A-2360, Waterous AFC-2500, or AVK Series 25 with an epoxy-coated interior and exterior cast iron or ductile iron body, pressure rating 250 psi, bronze-mounted, AWWA C509. Resilient seat (wedge) rubber encapsulated gate, flanged, or mechanical joint as required. Valves with ring stem seal, two-inch (2") square operating nut, that open left must be used. Resilient wedge gate valves on all pipe sizes up to and including 12 inches are required.
Direction of opening: All District valves are to open left.
Gate valves in sizes through twenty-four inches (24") shall be of the iron body, non-rising bronze stem, resilient seated wedge type manufactured to equal or exceed ANSI/AWWA Standard C509-80 and the specific requirements outlined in these Special Provisions.
Valves shall have a bottle-tight working water pressure of 250 psi with zero leakage and be capable of flow in either direction.
End connections shall be mechanical joint and shall be furnished with all necessary joint materials.
Valve openings shall be furnished and installed with valve stacks and covers in accordance with District specifications.
Valve body, bonnet, stuffing box, and disc cast shall be manufactured of either gray or ductile iron.
The exterior of the valve shall have epoxy coating per AWWA standards, applied to the ferrous parts of the valve, except for finished or seating surfaces.
All internal ferrous metal surfaces shall be coated with a two-part thermosetting epoxy coating. The coating shall be non-toxic, impart no taste to water, protect all seating and adjacent surfaces from corrosion, and prevent build up of scale or tuberculation.
The valve shall be structurally designed so that if excessive torque is applied to the stem in the closing direction, with the disc seated, failure of the pressure retaining parts does not occur. Stem failure under such conditions shall occur externally at such a point as to enable the stem to be safely turned in the opening direction by use of a pipe wrench.
B. Valve Boxes
Valve boxes shall be Tyler 668-S, D&L M-9042 (with a M-9073 Extension), or East Jordan 8550 (with a 8560 Extension). All buried valves shall be provided with a six-inch (6") cast iron, valve box, screw type. The valve box shall be of a design which will not transmit shock or stress to the valve and which shall have enough extension capability to be raised to final street grade. The valve box shall be cast iron, adjustable screw type, with minimum five-inch (5") diameter shaft provided with cover, marked "Water".
C. Pressure Reducing Valves-Main Line
The District requires that every District-maintained pressure reducing valve (PRV) be a CLA-VAL 92G-01ABXCKDS as appropriate and determined by the Engineer. In addition, the PRV is to have the following features:
1. Pressure reducing pilotry with pressure control ranges for correct valve operation where installed. Pilot material shall be bronze body only, brass, and stainless-steel trim. Tubing shall be copper.
2. Epoxy coated interior and exterior suitable for potable water contact.
3. Dura-clean stem design shall be installed.
4. Valve opening shall be regulated by means of a "speed control valve" for flow control.
5. Ductile iron, globe body, minimum 150-pound ANSI flanges or as may be required by system pressures, bronze trim.
6. Pilotry flow-clean strainer and minimum of three (3) pilot cocks.
D. Pressure Reducing Valves-Bypass Line
The PRV shall be a CLA-VAL 90-01 valve, sized appropriately to allow low flow to bypass around the main PRV. The valve shall have a ductile iron globe body with screwed ends. Pilotry is to be equipped with a flow wye strainer and isolation cocks.
E. Air Release/Vacuum Valves
Shall be an APCO air vacuum combination valve sized by the engineer as manufactured by Valve and Primer Corporation or an equivalent valve that has been approved by the District. The valve shall have a cast iron body, cover, and baffle with a stainless-steel float. The seat shall be fastened into the valve cover, without distortion, and shall be easily removed, if necessary. Air release/vacuum valves shall be installed at all high points in the system on any main line extensions. A five (5') foot diameter manhole is required for this installation. (See Combination Air Valve/Vac and Manhole Detail).
4.04 FIRE HYDRANTS
A. Fire hydrants shall be Mueller Centurion A423 Mountain Hydrant, which conforms to AWWA Standard C502 with a working pressure of 250 psi. They also shall be six-inch (6") mechanical joint inlet, minimum 5 1/4 inches, compression-type main valve that closes with pressure, two 2 1/2-inch hose nozzles, one 4 1/2-inch pump nozzle, nozzle threads ANSI B26. Nozzles must be easily replaceable in the field with standard tools. Operating and cap nuts must be 1 1/2-inch, Number 17 National Standard hex main valve that open to the LEFT. An arrow cast on top of hydrant shall indicate direction of opening. There shall be a breakable section that permits clean break at or near ground level, preventing water loss in case of breakage. Working parts must be removable for maintenance or repair without excavation. Also required are operating mechanism non-wetting, oil reservoir lubricated, with O-ring seals and barrel drain bronze mounted with at least two (2) outlets, which operate automatically with main valve. Fire hydrants must be installed at the end of all main lines. Finish grade around the fire hydrant shall be a minimum of six inches (6") to a maximum of twelve inches (12") below the flange for the final grade and paving inspection.
B. Fire Hydrant Extension Sections
New Installations: Defined as new main extensions throughout the two-year (2) warranty period. All new installations shall be installed at the standard 7-foot to 9.5-foot of cover measured from the top of the pipe to finish grade. All fire hydrants shall consist of a single solid shaft. No fire hydrant extensions will be allowed. Any special circumstance will require written approval from the District prior to installation.
Existing Fire Hydrants: No more than one (1), two-foot (2') long, fire hydrant grade extension (extension section) shall be used or installed on fire hydrant assemblies.
All hydrants shall be installed with a guard valve to isolate the hydrant for repair while maintaining service to main. No service line taps will be allowed between the guard valve and hydrant. Guard valves shall be installed on the tee off of the water main.
The maximum distance from the guard valve to the fire hydrant shall not exceed fifty feet (50').
Fire hydrants shall be installed at the end of all dead-end mains.
C. Fire Hydrant Marker Flags
The Applicant shall purchase and install fire hydrant marker flags for all newly constructed fire hydrants. The required flag is a Nordic Flex Flag, FF2-72 inches.
D. Fire Hydrant Depth of Bury
Fire hydrant depth of bury will conform to Manufacturer's requirements.
4.05 SERVICE LINES
The following represents the requirements for service line construction:
A. Copper Tubing
Shall be Type K, soft copper. Connections are to be compression or silver-soldered.
B. Corporation Stops
Mueller 300 Ball Valve Number B-25008 or B25028, AWWA C800 constructed of all brass construction with compression connection.
McDonald Number 4701 BT, AWWA C800.
Ford cc/comp - FB-1000-G
Ford IPS/Comp - FB1100-G
C. Curb Stops
Mueller 300 Ball Curb Valve No. B25209, Ford B44, or McDonald 6100 T. Curb stops must have compression end connections, AWWA C800.
D. Curb Boxes
For curb stops up to 1": Mueller H10314 with 89982 lid or McDonald 5601 with 5601L lid. For curb stops larger than 1": Mueller H10314 with 89982 lid and Tyler 6500 Series Enlarged Base #144809 or McDonald 5603 with 5601L lid. Shaft diameter shall be 1" and the top of the shaft shall be a minimum of 18" from final grade and lid.
Ductile Iron Saddle: Mueller DE2A, JCM-402, Smith & Blair 313, Ford F202, McDonald 3825, 3826 or equal and approved by the District. The saddle must have a double flat strap design with ductile iron body. Said saddle must conform to AWWA C800.
4.06 GRANULAR BEDDING
Two types of bedding material are allowed: Screened rock and soil or select imported material, meeting the following gradation specification table:
|Total Percent Passing||by Weight|
|Sieve Size||Screened Rock||Soil or Select Import|
|1 1/2 inch maximum, and maximum of 10% of pipe diameter to 1/2 inch
|No. 4||0 to 10||30 to 100|
|No. 200||0 to 5||0 to 50|
|Minimum Compaction Requirement||Tamp to spring line to fill voids below pipe haunches
||90% of Standard Proctor placed at +/- 3% of Optimum Moisture
The maximum particle size of pipe bedding should generally not exceed 1 1/2 inches or 10 percent of the nominal pipe diameter, whichever is less. Bedding for small pipe such as service lines should generally have a maximum particle size not exceeding 3/4 inch. Bedding materials shall be free of topsoil, organic material, frozen matter, debris, or other deleterious material.
Screened rock used for waterline or sewer pipe bedding should be crushed, angular material that meets the requirements of ASTM D 2321, Class IA bedding material. The material should have not more than 10 percent passing the No. 4 (4.75 millimeter) screen, and less than 5 percent passing the No. 200 (75 micrometer) screen. The bedding should be tamped under the haunches of the pipe to spring line. Where future excavation is anticipated, the sloughing properties of screened rock when unconfined should be taken into consideration. The District may require soil or select import. Where groundwater may be present, the use of screened rock for bedding is prohibited.
Compacted pipe bedding should meet the requirements of ASTM D 2321, Class IB, Class II, or Class III bedding material. The material should have a minimum of 30 percent passing the No. 4 screen and less than 50 percent passing the No. 200 screen. Class 6 aggregate base course per CDOT Table 703.2 conforms to this gradation criteria. The bedding should be compacted to a minimum of 90 percent at +/- 3 percent of optimum moisture content, referencing Standard Proctor (ASTM D698, AASHTO T99). Material containing 10 to 30 percent passing the No. 4 screen can be used with the following considerations: materials in this range can be expected to possess properties similar to screened rock except that compaction will be required and materials in this range may be too free-draining to be testable for compaction by ASTM D698.
Flow-fill, a 1/2 sack (50 pounds) per cubic yard lean concrete mix as defined in the CDOT 1999 Standard Specifications for Road and Bridge Construction, Section 206.02, may be used as bedding where a combination of ease of placement, low permeability, and unconfined stability is desired.
- Bedding materials shall be free of topsoil, organic materials, frozen matter, debris, or other deleterious materials.
- Flow-fill as specified by CDOT 1999 Standard Specifications, Section 206.02, may be used with District approval.
- Ductile Iron Pipe may be required to be encased in loose polyethylene in conformance with ANSI/AWWA C105/A21.5 installation methods, unless site soils and proposed bedding materials are determined to be non-corrosive to iron pipe when evaluated according to Appendix A of ANSI/AWWA C105/A21.5.
- Materials not meeting these requirements shall be used only with prior written approval of the District.
In specific areas, such as where access is extremely limited, the use of on-site materials may be allowed, and, when used, must be on-site 1 1/2 inches minus well-graded screened material, free from organic materials, chunks of soil, frozen material, debris, or other suitable materials. Use of on-site bedding material must have prior written District approval.
4.07 POLYETHYLENE ENCASEMENT
A polyethylene encasement material shall be manufactured in accordance with AWWA C105, with the following requirements. The raw material used to manufacture polyethylene film shall be Type 1, Class A, Grade E1, in accordance with ASTM D1248.
4.08 MARKING TAPE
The installation of "blue" marking tape is required on all water mains and service lines. The tape shall be installed approximately twenty-four inches (24") above the main or line. The tape shall meet the following specifications:
1. Four (4) mil thick PVC material.
2. Solid "blue" color with black lettering.
3. Six inches (6") in width.
4.09 TRENCH BACKFILL
Shall be backfilled with same materials excavated from work site unless unsuitable. rocks over six inches (6") in diameter shall not be used within 12 inches above the bedding material as backfill material. No backfill material with boulders larger than 18 inches in diameter shall be backfilled in the trench.
4.10 THRUST BLOCKS AND ANCHORS
Thrust blocks may be eliminated if megalugs have been engineered.
Concrete thrust blocks and anchors should be used in conjunction with megalugs and be sized for the maximum internal pipe pressure and soil bearing capacity. Standard sizes and shapes of thrust blocks and anchors are shown on details. No thrust block shall be smaller than that size required for an eight-inch (8") main fitting.
Thrust reaction blocking shall be concrete of a mix not leaner than one (1) part cement to 2 1/2 parts sand and five (5) parts stone, and having a compressive strength of not less than 3,000 psi after 28 days.
All thrust blocks shall be formed in accordance with the District's Specifications. See Concrete Thrust Blocks detail.
The District shall inspect all thrust blocks.
A. General: All materials shall be furnished from sources agreed to by the District and Engineer.
B. Cement: ASTM C-150 for Portland Cement, Type II. Cement that has become partially set or contains lumps of caked cement shall be rejected.
C. Aggregate: ASTM C33.
D. Water: Water used in mixing or curing concrete shall be clean and free from oil, acids, salt, alkali, or organic materials harmful to concrete.
A. Design Mix
a. Cement 5 1/2 sacks per cubic yard
b. Coarse aggregate - 43 percent (%)
c. Water - 5.5 gallons per sack
d. Maximum size aggregate - 3/4 inch
2. Slump: Four inches (4") maximum
3. Strength: Minimum 3,000 psi at 28 days
4. Air Content: 5 percent (%) - 7 percent (%)
B. Job-Mixed Concrete
The concrete shall be mixed in drum mixer conforming to the Concrete Paving Mixer Standards of Mixer Manufacturers Bureau of Associated General Contractors of America. Mixer shall be capable of combining aggregates, cement, and water into a thoroughly mixed and uniform mass.
C. Ready-Mixed Concrete
Proportioned, mixed, and transported in accordance with ASTM C94. Any concrete not plastic and workable when it reaches the project shall be rejected.
4.11 PRESSURE REDUCER VAULTS
All proposed installations shall be "factory-built" vaults including the appropriately sized main line inlet and outlet.
PRV installations shall include an appropriately sized manual bypass with an approved gate valve; two (2) appropriately sized CLA-VAL Model 90G-01ABKC pressure reducing valves with approved isolating gate valves.
All vault installations shall include a 120/240 volt power panel; all assembled, tested and painted. Minimum dimensions of the vault shall be 7' (H) x 8'(L) x 6'(W), skid -mounted capsule with Bilco Model MNB-50 access hatch, ladder, fluorescent light, gravity drain in sump, dehumidifier, 240 volt heater, exhaust fan and two (2) magnesium anode packs. All proposed vault installations must be pre-approved by the District.
4.12 CASING SPACERS
Carrier pipes to be installed inside casings shall be installed with self-restraining casing spacers. Casing spacers shall provide axial thrust restraint to prevent pipe joint deflection during and after installation. They shall also provide dielectric insulation between the carrier pipe and the casing and facilitate installation of the carrier pipe into the casing.
Restrained casing spacers shall be provided at all pipe joints. In addition, casing spacers shall be installed every ten (10') feet of the pipeline to support the pipe barrel and the weight of its contents. Restrained casing spacers shall be Uni-Flange Series UFRCS1300 or UFRCS1390 or approved restrained joint devices with Cascade Waterworks Mfg., Co., Model CCS casing spacers or an approved equal.
CHAPTER 5 - EARTHWORK
5.01 EARTHWORK DEFINED
Earthwork shall include all Contractor clearing, grubbing, grading, excavation, fill, backfill, excess excavation, bedding material, borrow material, and surface restoration as may be required to complete the work.
5.02 BARRICADES, GUARDS, AND SAFETY PROVISIONS
Adequate barricades, construction signs, safety flasher lights and flag persons as required shall be placed and maintained to protect persons from injury and to avoid property damage during the progress of the construction work and until it is safe for traffic to use the roadway. All material piles, equipment and pipe that may serve as obstructions to traffic shall be enclosed by fences or barricades and shall be protected by proper lights when the visibility is poor. All safety and traffic rules and regulations of local authorities shall be observed. All barricading and detours shall be coordinated with the appropriate entity including any special Districts, Eagle County, Town of Vail, Town of Avon, Town of Minturn, or Colorado Department of Transportation (CDOT), and shall be in accordance with said regulations.
5.03 MAINTENANCE OF TRAFFIC AND CLOSING OF STREETS
The Contractor shall carry on the work in a manner that will cause the least interruption in traffic.
All barricading, signage and detours shall be coordinated with the appropriate regulating entity including Eagle County, Colorado Department of Transportation (CDOT), Special Districts, the Town of Vail (TOV), Town of Avon (TOA), or the Town of Minturn (TOM) and shall be in accordance with said regulations.
5.04 CAUTION IN EXCAVATION
The Contractor shall proceed with caution in the excavation and preparation of the trench so that the exact location of all underground utilities and structures may be determined, and he or she shall be held responsible for the repair of such utilities and structures when broken or otherwise damaged because of negligence or carelessness on his or her part.
5.05 EXCAVATION TO LINE AND GRADE
All excavations shall be made to the lines and grades as established by the approved drawings and the Specifications. Trenches shall be excavated to the depth required to provide a uniform and continuous bearing and support for the pipe bedding on solid undisturbed ground at every point between bell holes. (Bell holes shall be provided at each pipe joint to permit the joint to be made properly.) Any part of the bottom of the trench excavated below the specified grade shall be corrected with approved material and thoroughly compacted. The finished grade of the trench shall be prepared accurately by means of hand tools.
5.06 TRENCHING OPERATIONS
The trench shall be excavated in a manner that will allow the pipe to be installed to the alignment and depth required. The trench shall be excavated only so far in advance of the pipe installation as is necessary to expedite the work.
A. Trench Width
All existing asphalt or concrete surfacing shall be saw cut vertically in a straight line, and removed from the job site prior to starting the trench excavation. This material shall not be used in any fill or backfill.
The trench shall be excavated so that a minimum clearance of six inches (6") shall be maintained on each side of the pipe for proper placement and compaction of the bedding or backfill material. Large rocks, boulders, and stones shall be removed to provide a clearance of at least six inches (6") below and on each side of all pipe, fire hydrants, valves, and fittings. The specified minimum clearances are the minimum clear distances that will be permitted between any part of the pipe and appurtenances being installed and any part, projection, or point of such rock, boulder, or stone.
B. Trench Support
The trench shall be adequately supported and the safety of workers provided for as required by the most recent standards adopted by the Occupational Safety and Health Administration (OSHA) Standards Board. Sheeting and shoring shall be utilized where required to prevent any excessive widening or sloughing of the trench, which may be detrimental to human safety, to the pipe, and appurtenances being installed, to existing utilities, to existing structures, or to any other existing facility or item.
C. Excavated Material
Excavated material shall not be placed closer than two feet (2') from the top edge of the trench. Heavy equipment should not be used, or placed near the sides of the trench unless the trench is adequately braced.
All excavated material shall be piled in a manner that will not endanger the work and that will avoid obstructing traffic. Hydrants under pressure, valve lid covers, valve boxes, or other utility controls shall be left unobstructed and accessible until the work is completed.
5.07 EXCAVATION IN POOR SOIL
If materials below the excavation subgrade for pipes or structures are found to be soft or unstable or include ashes, cinders, refuse or organic material, or fragments of inorganic material that cannot, in the opinion of the District Inspector and/or the geotechnical engineer, satisfactorily support the pipe or structure, the contractor shall further excavate to remove the unsuitable material. The over-excavated volume shall be replaced with compacted materials as recommended by the geotechnical engineer back to pipe or structure subgrade. The pipe or structure can then be installed per specifications.
5.08 PROTECTION OF EXISTING STRUCTURES AND UTILITIES
Adequate protection, temporary support and maintenance of all underground and surface structures, utilities and other obstructions encountered in the progress of the work shall be furnished by the Contractor at his expense and under his direction. Any structures, utilities, or obstructions disturbed or damaged shall be immediately restored or replaced by the Contractor.
5.09 SURPLUS EXCAVATION MATERIAL
All surplus excavation shall be removed from the job site and disposed of properly. If the surplus excavation is disposed of on private property, prior written permission shall be obtained from the owner of the property and submitted to the District Inspector. All materials must be removed in a timely manner and to the satisfaction of the District Inspector.
In general, blasting will be allowed in order to expedite the work if a permit by the local authority having jurisdiction is granted. All explosives and appurtenances shall be transported, handled, stored, and used in accordance with the laws of the local, state, and federal governments, as applicable.
All blasting shall be controlled so as not to injure any existing structure, utility or facility. The protection of life and property and all liability for blasting shall be placed solely on the person or persons conducting the blasting operation. The hours of blasting shall be in accordance with the permit of the local authority.
All pipe trenches or structure excavation shall be kept free from water during pipe installation and other related work. The method of dewatering shall provide for a completely dry foundation at the final lines and grades of the excavation.
Dewatering shall be accomplished by the use of well point, sump pumps, rock or gravel drains placed below subgrade foundations or subsurface pipe drains. All water shall be disposed of in a suitable manner without being a menace to public health or causing public inconvenience. No water shall be drained into other work being completed or under construction.
The dewatering operation shall continue until such time as it is safe to allow the water table to rise in the excavations. Pipe trenches shall contain enough backfill to prevent pipe flotation. When pipe is installed in a casing or tunnel longer than 30-pipe diameters, the pipe inside the casing or tunnels shall be secured so flotation does not occur when the pipe is empty.
Water shall not be allowed to rise until any concrete has set and the forms have been removed. Water shall not be allowed to rise unequally against unsupported structural walls.
5.12 SELECT PIPE BEDDING
When indicated on the plans or drawings or when, in the opinion of the District, select bedding material is required, preparation and installation shall be as follows:
A. Installation of Bedding and Pipe
After completion of the trench excavation and proper preparation of the foundation, six inches (6") of bedding material shall be placed on the trench bottom for support under the pipe. Bell holes shall be dug deep enough to provide a minimum of two inches (2") of clearance between the bell and bedding material. All pipes shall be installed in such a manner as to ensure full support of the pipe barrel over its entire length. After the pipe is adjusted for line and grade, and the joint is made, the bedding material shall be carefully placed and tamped under the haunches of the pipe and in the previously dug bell holes. Refer to details in the Specifications for additional information.
Compaction is herein defined as the act of placing approved bedding material under the haunches of pipe, paying particular attention to voids, bell holes, and sling holes. The purpose of tamping is to ensure uniform support for the pipe.
For ductile iron and steel pipe, the limits of bedding shall be from six inches (6") below the bottom of the pipe to 12 inches above the top of the pipe. Approved backfill may then be installed to the ground line.
B. Granular Bedding Material
The granular bedding material shall be clean and free of corrosive properties and shall conform to the gradation limits specified in the Material Specifications chapter.
5.13 BACKFILL AND COMPACTION
Backfill shall be consolidated and/or compacted by vibrating, tamping, or a combination thereof, to the satisfaction of the appropriate controlling authority; however, the District shall require that in all instances where the trench is within limits of pavement, shoulders of roads, sidewalks, or major improvements compaction of predominately cohesive soils shall not be less than 95 percent (95%) ASTM D698, + 2 percent (2%) optimum moisture content. For non-cohesive soils compact to not less than 70 percent (70%) relative density per ASTM D4253/D4254, or the more restrictive local specification. Where trenches are outside pavement and located in areas where trench settlement can be tolerated, the compaction of the cohesive soil shall not be less than 90 percent (90%) ASTM D698, + 2 percent (2%) optimum moisture content.
It is expected that the trench excavation will provide suitable backfill material. Wet, soft or frozen material, asphalt and concrete chunks, cinders, ashes, refuse, vegetable or organic material, boulders, rocks or other deleterious substances shall not be used for backfill. If the excavated material is not suitable for backfill, as determined by the District, suitable material shall be hauled in and utilized, and the rejected material hauled away and disposed of properly.
Bedding material shall be compacted around and under pipe. Backfill materials shall be deposited in the trench for its full width on each side of the pipe, fittings and appurtenances simultaneously.
From the centerline of the pipe, fittings, and appurtenances to a depth of 12 inches above the top of the pipe, the trench shall be backfilled by approved mechanical methods. Special care shall be used in placing this portion of backfill so as to avoid disturbing the pipe.
From 12 inches above the pipe to finish grade, the trench shall be backfilled by approved mechanical methods.
The District will require copies of all compaction reports to be submitted to District Inspectors to ensure compaction compliance.
Upon completion of the work, all rubbish, unused materials, concrete forms and other like materials shall be removed from the job site. All excess excavation shall be disposed of as specified and all areas shall be left in a state of order and cleanliness. Cleanup shall be performed within ten (10) days of the completion of construction or in accordance with an acceptable arrangement made between all parties involved.
5.15 SURFACE RESTORATION AND MAINTENANCE
A. Surfaced Areas
The Contractor shall obtain the necessary permits for the project. In addition, the Contractor will remove pavement and road surfaces as part of the trench excavation. The width of pavement removed shall meet the standards of the governing agency. The Contractor shall use such sawing method as will assure the breaking of the pavement along straight lines. The cut face of the remaining pavement shall be approximately vertical.
The Contractor shall bring all existing appurtenances to current District standards. The Contractor shall restore all pavement, sidewalks, curbing, gutters, or other surface structures removed or disturbed as part of the work to a condition meeting the standards of the governing agency, and shall furnish all incidental labor and materials. No permanent pavement shall be restored until the condition of backfill is such as to properly support the pavement.
B. Unsurfaced Areas
All surface cuts shall be, as a minimum requirement, restored to a condition equal to that prior to construction. All streets, roadways, or right-of-ways shall be restored in accordance with the regulations and requirements of the agency having control or jurisdiction over the street, roadway, or right-of-way.
C. Damaged Surfaces and Property
If any pavement, street, shrubbery, sod, rock, fences, poles or other property and surface structures have been damaged, removed or disturbed by the Contractor, whether deliberately or through failure to carry out the requirements of the controlling agency or the specific directions of the District, or through failure to employ usual and reasonable safeguards, such property and surface structures shall be replaced or repaired, to original condition and to the satisfaction of the Applicant, at the expense of the Contractor. All restoration shall be performed in a timely manner not to exceed three (3) working days and to the satisfaction of the District Inspector or by a date mutually agreed upon by the District, Applicant and Contractor and Applicant.
5.16 SUBGRADE AND ROAD PREPARATION
Prior to installation of water mains in dedicated streets, road construction must have progressed to at least the subgrade stage. Subgrade elevation is defined as an elevation that lies approximately eight inches (8") below the finished street grade.
CHAPTER 6 - PIPE INSTALLATION
Safety of workers shall be provided as required by the Occupational Safety and Health Act (OSHA).
6.02 HANDLING OF MATERIALS
Pipe and fittings shall be loaded and unloaded by lifting so as to avoid shock or damage. Under no circumstances shall such material be dropped. If, however, any part of the pipe is damaged, the replacement or repair of the damaged pipe shall be done to the satisfaction of the District. Any pipe or fittings that are not acceptable to the District shall be removed from the job site immediately. All pipe-handling equipment and pipe handling methods shall be in accordance with the methods and equipment recommended by the manufacturer. Under NO circumstance shall forks be inserted into any pipe and or fitting.
6.03 INSPECTION AND PREPARATION OF PIPE AND FITTINGS
Before placing pipe in the trench, each pipe or fitting shall be thoroughly cleaned of all foreign material, kept clean at all times thereafter, and carefully examined for cracks and other defects before installation. Bell ends and spigot ends are to be examined with particular care.
All lumps, blisters and excess coatings shall be removed from the pipe and fitting, and the outside of the spigot and the inside of the bell shall be wiped clean, dry and free from oil and grease before the pipe or fitting is installed. Dirt and any other material must be removed from the barrel of the pipe before installation.
6.04 CUTTING AND FITTING OF PIPE
Pipe shall be cut in accordance with manufacturer's recommendations, whenever necessary, to conform to location of fittings, line, or grade. All cuts shall be straight and true and beveled, when required, and completed in a workmanlike manner. All burrs shall be removed from the ends of cut pipe.
6.05 PIPE JOINT LUBRICATION
Joint lubricant shall be supplied by the pipe manufacturer. Joint lubricant shall be non-toxic and water-soluble.
6.06 PIPE JOINTS
All pipe joints shall be uniform and smooth transitions shall exist from joint to joint or fitting.
6.07 PIPE ALIGNMENT AND GRADE
Fittings, valves, and hydrants shall be installed at staked locations and elevations; spigots centered in bells; and all valve and hydrant stems plumb.
For main installations, a Professional Land Surveyor registered in the State of Colorado shall set stakes for alignment and grade.
When installing pipe on curves, the intent is to install to the staked alignment. The pipe shall be kept in alignment by placing bends on the curve. PIPE DEFLECTIONS ARE DISCOURAGED. If pipe deflections must be constructed, deflections up to 50 percent (50%) of the manufacturer's recommendations shall be permitted. All deflections must be field verified and reflected in the final submittal as-built drawings.
Pipe shall be installed with the bell ends facing in the direction of installation, unless directed otherwise by the District. Where pipe is to be installed on a grade of 10 percent (%) or greater, the installation shall start at the bottom and shall proceed upward with the bell ends of the pipe up grade.
6.08 TEMPORARY PLUGS
Whenever the pipe is left unattended, temporary plugs shall be installed at all openings. Temporary plugs shall be of such design as to prevent water, debris, children, and animals from entering the pipe. The Contractor shall provide all temporary plugs. The temporary plug shall be secured in a fashion that it cannot be lost in the pipeline.
No pipe or appurtenant structure shall be installed upon a foundation into which frost has penetrated, or if at any time there is danger of ice formation. No pipe or appurtenant structure shall be installed unless backfilling can be completed before the formation of ice and frost.
6.10 LOWERING OF MATERIAL INTO THE TRENCH
Proper implements, tools and facilities satisfactory to the District shall be provided and used by the Contractor for the safe and convenient performance of the work. All pipe, fittings, valves, and hydrants shall be carefully lowered into the trench piece by piece by means of a derrick, ropes, or other suitable tools or equipment, in such a manner as to prevent damage to main materials and their protective coatings and linings. Under no circumstances shall main materials be dropped or dumped into the trench.
If damage occurs to any pipe, fitting, valves, hydrants or water main accessories in handling, the damage shall be immediately brought to the attention of the District.
6.11 INSTALLATION OF PIPE
Every precaution shall be taken to prevent foreign material from entering the pipe while it is being placed in the trench. If the pipe installation crew cannot put the pipe into the trench and in place without getting dirt into the pipe, the Contractor shall place a heavy, tightly woven canvas bag of suitable size over each end before lowering the pipe into the trench and said canvas bag shall be left in place until the connection is to be made to the adjacent pipe. During installation operations, no debris, tools, clothing or other materials shall be placed in the pipe.
As each length of pipe is placed in the trench, the spigot end shall be centered in the bell and the pipe pushed home with a slow steady pressure without jerky or jolting movements and brought to correct line and grade. The pipe shall be secured in place with approved backfill material tamped under it, except at the bells. Precautions shall be taken to prevent dirt from entering the joint space. No wooded blocking shall be left at any point under the pipeline. If road base or screened native material has been approved and is used, compaction shall occur below, beside, and above the pipe.
No pipe shall be installed when trench conditions are unsuitable.
Temporary manufactured plugs shall be inserted into the ends of the pipe during construction and during unattended times to ensure that debris does not enter the water main.
B. Ductile Iron Pipe
1. Push-On Joint
A thin film of District approved gasket lubricant shall be applied to either the inside face of the gasket, or the spigot end of the pipe, or both. The spigot end of the pipe shall be placed in the bell end with care to prevent the joint from contacting the ground. Pipe furnished without a depth mark on the spigot end shall be marked before assembly to ensure insertion to full depth of the joint. The pipe shall be kept in straight alignment and the joint shall be completed by pushing the pipe home with a slow, steady pressure without jerky or jolting movements by using a forked tool, jack-type tool, or other device approved by the District. The District recommends that a backhoe not be used to push-home pipe with push-on joints. However, if pipe is pushed home with a backhoe bucket, a wooden shield must be placed between the backhoe and the end of the pipe. The spigot end of field cut pipe lengths shall be filed or ground to resemble the spigot end of such pipe as manufactured.
Upon completion of joining push-on joint pipe, an inspection shall be made to ensure that the gasket is correctly aligned in the gasket recess of the bell socket and not twisted or turned.
Joint bonding is to be completed using conductor wire and cadwelds or by connecting the copper bonding straps using manufacturer supplied silicon bronze hex head bolts and nuts.
2. Mechanical Joint Fittings and Pipe
Before joining mechanical joint ductile iron fittings to cast iron, ductile iron, or PVC pipe, the outside of the spigot, the inside of the bell and the rubber gasket shall be thoroughly cleaned to remove oil, grit, excess coating, and other foreign matter.
The joint is to be lubricated with a manufacturer's recommended pipe gasket lubrication.
The ductile iron gland shall be slipped on the spigot end of the pipe with the lip extension of the gland toward the socket, or bell end. The rubber gasket shall be placed on the spigot end with the thick edge toward the gland.
The pipe shall be pushed in until the spigot end fully penetrates the bell. The gasket shall then be pressed into place within the bell evenly around the entire joint. The ductile iron gland shall be moved along the pipe into position for bolting; the bolts inserted and the nuts screwed finger tight, then tightened with a torque-limiting wrench. Torque for the various sizes of bolts shall be as follows:
|5/8"||45 - 60|
|3/4"||75 - 90|
|1"||85 - 100|
|1 -1/4"||105 - 120|
Nuts spaced 180 degrees apart shall be tightened alternately in order to produce equal pressure on all parts of the gland.
Joint bonding shall be completed by using conductor wire and cadwelds or by connecting the copper bonding straps using manufacturer supplied silicon bronze hex head bolts and nuts.
C. Marking Tape
The installation of "blue" marking tape is required on all water mains and service lines. The tape shall be installed approximately 24-inches (24") above the main or line. The tape shall meet the following specifications:
1. 4-mil thick PVC material.
2. Solid blue color with black lettering.
3. Six inches (6") in width.
6.12 INSTALLATION OF VALVES
Valves shall be handled in such a manner as to prevent any injury or damage. All joints shall be thoroughly cleaned before installation.
Valves shall be set and joined to the pipe in the manner previously specified for cleaning, installing and joining push-on and mechanical joint pipe. Valves shall be set in such a manner that the valve stems are plumb. Valves shall not be blocked using precast concrete blocks except in wet tap valve applications where precast concrete blocks should be used. NO WOOD BLOCKING WILL BE ALLOWED.
Valves shall be operated prior to installation to ensure good operating condition.
6.13 VALVE BOX INSTALLATION
A valve box shall be provided for every valve. The valve box shall not transmit shock or stress to the valve, and shall be centered and plumb over the operating nut of the valve, with the box cover set to the required elevation. It will be the responsibility of the Applicant to insure that valve boxes are plumb and raised to the proper elevation.
6.14 INSTALLATION OF FITTINGS
All buried fittings in the system shall be mechanical joint applications.
Ductile Iron Pipe: All joints shall have a cadweld installed using a number four (4) gauge solid copper wire or the manufacturer's provided bonding strap. Cadwelds shall be installed in accordance with the manufacturer's recommended application/procedure. In addition, a ten-gauge (10) insulated tracer wire shall be installed along all main line extensions.
6.15 FIRE HYDRANTS
The location of all hydrants shall be staked. Final location and grade shall be in accordance with the approved drawings. Offset stakes not farther than 12 feet from the fire hydrant are acceptable. All hydrants shall stand plumb.
Each hydrant shall be connected to the main by a six-inch (6") branch line. An independent six-inch (6") gate valve shall be installed on the tee off of the water main. It is the intention of the District to limit the length of the six-inch (6") branch line servicing the fire hydrant to 50 feet. If the length of the branch line extends beyond 50 feet, an eight-inch (8") main with an eight-inch (8") by six-inch (6") concentric reducer shall be used from the main until a point 50 feet from the hydrant is reached. At that point, a six-inch (6") branch line may be extended to the fire hydrant.
No service line connections shall be installed between the fire hydrant and the fire hydrant guard valve. No service line connections shall be made on the six-inch (6") branch line servicing the fire hydrant.
The shoe of each hydrant shall be well braced against the un-excavated earth at the end of the trench with a concrete thrust block. Care shall be taken not to cover the weep holes with concrete. The bottom of the hydrant bowl and the hydrant valve shall be supported with minimum 18 x 8 x 4-inch precast concrete blocking slabs or a District approved equal. The hydrant assembly shall require megalug restraints.
Wherever a hydrant is set, drainage shall be provided at the base of the hydrant by placing approved granular bedding material from the bottom of the trench, to at least 12 inches above the barrel flange of the hydrant, and as shown on the typical fire hydrant detail. The minimum distance from the bottom of the trench to the bottom of the hydrant elbow shall be six inches (6"). The minimum of approved granular bedding material placed therein shall be 1/3 cubic yards.
The minimum clearances around all fire hydrants shall be: ten feet (10') in the front, seven feet (7') on the sides, four feet (4') on the back, and 20 feet above.
E. Operation of Fire Hydrant
The required operational position of a fire hydrant is either fully opened or fully closed. The guard valve shall control any restriction of flow. The restriction of flow, through a fire hydrant, by means of the "operating nut" is strictly prohibited.
6.16 DEAD ENDS
A fire hydrant shall be installed at the end of each dead-end main.
6.17 THRUST BLOCKS AND ANCHORS
Thrust blocks and/or anchors shall be constructed at all bends, tees, plugs, fire hydrants, and fittings that require reaction support due to unbalanced line thrust. Care shall be taken not to block outlets or to cover bolts, nuts, clamps, or other fittings or to make them inaccessible. Bearing surface areas are minimum areas to bear against the undisturbed trench wall. In every instance, the thrust block or anchor shall bear against undisturbed earth. Care shall be taken not to cover nuts, bolts, etc., with concrete.
All debris, water or ice shall be removed from the place to be occupied by the concrete. Concrete shall not be placed on frozen subgrade. If backfilling is to occur before concrete sets, a concrete form must be used.
B. Form Work for Thrust Blocks and Anchors
All concrete thrust blocks and anchors shall be formed in accordance with the District's Specifications. See Concrete Thrust Blocks detail. A plastic bond-breaker must be provided around all portions of the main to keep concrete from adhering to pipe and fittings.
No thrust block shall be smaller than that size required for an eight-inch (8") main fitting. See Concrete Thrust Blocks detail.
C. Concrete and Curing Time
Thrust blocks shall be concrete of a mix not leaner than one (1) part cement to 2 1/2 parts sand and five (5) parts stone, and having a compressive strength of not less than 3,000 psi after 28 days.
Minimum uncovered curing time for concrete thrust blocks regardless of additives shall be 36 hours for anchors containing two (2) cubic yards or less, 48 hours for anchors containing more than two (2) cubic yards but less than six (6) cubic yards, and 72 hours for anchors containing more than six (6) cubic yards but less than 12 cubic yards.
No water main will be charged or pressurized without the approval of the District. All thrust blocks and anchors must meet the minimum curing time.
D. Compaction of Fill Over Thrust Blocks and Anchors
Backfill may be placed over thrust blocks and anchors once the surface has set sufficiently to resist the weight of the backfill and compaction.
Megalugs shall be used in conjunction with all thrust blocks.
6.18 AIR VAC VAULTS
Vaults shall be precast or poured-in-place concrete and shall be constructed in accordance with District specifications. Precast vaults shall be designed that all joints and corners are waterproof. Precast vaults shall be made waterproof after construction by use of sealant, epoxies, or other approved methods. All dimensions, locations and elevations shall be coordinated by the Applicant and Contractor and meet the requirements of the District. All fittings within the vault shall be rated to at least the highest pressure expected within the vault. Air Vac Vaults installed in high groundwater areas shall be completely sealed (see High Groundwater Air Vac Vault detail).
Megalugs shall be used in conjunction with all mechanical joint bends and fittings in all new pipeline installations. Thrust blocks may be eliminated if megalugs and restrained pipe joints have been engineered. Engineering calculations, if required, must be submitted with construction drawings.
6.20 CONNECTION TO THE DISTRICT SYSTEM
Connections to the District system shall be in a neat and workmanlike manner. The connection shall be inspected and approved by the District. Under no circumstances shall a non-disinfected main, which cannot be isolated, be connected to an existing distribution main in service.
B. Tapping Existing Mains
Main Line Connections: Unless otherwise approved by the District, all main line connections shall be made by means of a tee.
Service Taps/Stubouts: During new main line construction, service line stubouts may only be installed after the required tests have been completed and approved by the District. Stubouts shall be installed by the main line Contractor. Stubouts shall terminate at the curb stop valve. Curb stop valves shall be installed at the property line or edge of easement. The minimum separation distance between service line taps on the main shall be 18 inches.
The Contractor shall install all new service line taps.
All tees/taps shall be witnessed and approved by the District. Any tap preformed without a District inspection and approval shall be considered "illegal system tampering" and subject to a one thousand dollar ($1,000) fine.
C. Operation of Valves
In connecting to the District system, it may be necessary to operate existing District valves. Only District personnel shall operate valves on the District system, and shall only access system to make connections. The Contractor shall give the District Inspector 48 hours notice to arrange for operating valves. Both the Contractor and the District Representative shall be present when the valves are operated.
D. Interruption of Service
Installation of a connection that will require closing existing valves may cause an interruption of water service to existing District customers. All interruptions of service shall be coordinated with the District Inspector.
Notification: The Contractor shall deliver written notice to all affected customers at least 48 hours prior to the proposed shut down. The notice shall state the date, time, and probable duration of shutdown, the name and telephone number of the Contractor, District, and District Inspector.
The local fire department for the affected area shall also be notified 48 hours in advance. A description of the boundaries of the affected area and the location of all fire hydrants in that area shall be provided to the fire department.
The Contractor will arrange for all notification to both residential customers and the fire department. The Contractor will be responsible to furnish the District all necessary information as to the date and time that the interruption will begin and the total time required to complete the installation.
If, in the process of installing a connection, there exists an industry or building in the area that cannot be out of water, such as a hospital, or other special customers, appropriate means shall be taken to provide and convey water. The District shall approve water conveyance in writing.
General: The District reserves the right to schedule water system shut downs that will provide the least inconvenience to the general public.
Tie-In Procedures: Water line tie-in trenches shall be excavated on the day prior to shutdown unless otherwise approved by the Engineer in order to verify the materials required for tie-in and to minimize construction time on the day of the shutdown. The pre-excavated tie-in trench shall be shored and covered with a steel plate to provide temporary surfacing unless the tie-in is postponed for more than one day beyond the scheduled time. All required pipeline tie-in materials shall be delivered to the site prior to the shutdown.
6.21 CORROSION PROTECTION SYSTEMS
A. Dissimilar Materials
Cathodic protection and insulation shall be installed as required by the District. Particular care shall be taken to insulate between dissimilar materials.
B. Insulating Joints
Whenever it is necessary to join pipe of dissimilar metal, or when designated by the District, a method of insulating against the passage of electrical current, approved by the District, shall be provided. Special care shall be exercised during the installation of these joints to prevent electrical conductivity across the joints.
6.22 DISINFECTION AND TESTING
The following procedure shall apply to all main extensions within the District service area. Pipe extensions shall be chlorinated in accordance with AWWA C600 and C651.99 Standard for Disinfecting Water Mains.
THE CHLORINATION OF THE FINISHED PIPELINE SHALL BE DONE PRIOR TO THE INSTALLATION OF ANY SERVICE TAPS.
Before filling the pipe with water, the pipe shall be clean and free of debris to the satisfaction of the District.
Disinfecting by chlorination of the pipe shall be performed prior to acceptance by the District. The chlorinating agent, and method of application, shall be in accordance with AWWA C651.99. The Contractor shall provide material for disinfecting of water mains.
Calcium hypochlorite granules shall be placed at the upstream end of the first section of pipe, at the upstream end of each branch main, and at 500-foot intervals. The quantity of granules shall be as shown in the table below. This method may be used only if the pipes and appurtenances have been kept cleaned and dry during construction. This method is not to be used on solvent welded plastic or on screwed joint steel pipe because of the danger of fire or explosion from the reaction of the joint compound with the calcium hypochlorite.
The District does not allow the use of calcium hypochlorite tablets due to the cold water and the time it takes to completely dissolve the tablets.
CALCIUM HYPOCHLORITE GRANULES
To be placed at the beginning of main and at each 500-foot interval.
|16" and larger||40.2|
After the pipe is filled with water and chlorine, the chlorinated water shall be held in contact with the pipe for 24 hours. At the end of the 24-hour period, the water in the pipeline shall be tested by the District to ensure residual chlorine content of not less than 25 mg/L. The pipeline shall then be thoroughly flushed to remove the heavily chlorinated water and/or debris. Care shall be taken in flushing the pipeline to prevent property damage and danger to the public. Discharge of highly chlorinated water shall not be released directly to any stream, watercourse or sanitary sewer.
After chlorination, the water shall be flushed from the line at its extremity until the replacement water is equal, chemically and bacteriologically to those of the permanent source of supply (shall not exceed 1 (one) part per million).
After final flushing and before the new water main is connected to the distribution system, two consecutive sets of acceptable samples taken at least 24 hours apart, shall be collected from the new main. At least one set of bacteriological samples shall be collected from every 1200-feet of the new water main, plus one set from the end of the line and at least one set from each branch. The bacteriological samples must come back negative and a chlorine residual must be taken before the line is put into service. Testing of residual chlorine and bacteriological sampling and testing will be done by the District.
If the initial disinfection fails to produce satisfactory bacteriological results, the new main shall be re-flushed and shall be re-sampled. If check samples also fail to produce acceptable results, the main shall be re-chlorinated until satisfactory results are obtained. The re-sampling and disinfection will be performed at the developer's expense.
The environment to which the chlorinated water is to be discharge shall be inspected. If there is any possibility that the chlorinated discharge will cause damage to the environment, then a neutralizing chemical shall be applied to the water to be wasted to neutralize thoroughly the residual chlorine.
If the "continuous feed method" or the "slug method" of chlorination is used, the Contractor is to provide the written procedure to the District Inspector for acceptance of the method at least 48 hours prior to starting the work.
No main, which has been disinfected and flushed, shall stand stagnant for more than 15 days without being re-flushed and a new disinfecting test performed, passed, and approved by the District. No main shall be tapped until the main has been flushed of all "highly chlorinated" water.
6.23 HYDROSTATIC PRESSURE TESTING
The parameters for hydrostatic testing are as follows:
A. General: Make pressure and leakage tests on all newly installed pipe. Test two (2) or more valved sections not to exceed 1,000 feet (if requested by the District). Test the first section of pipe installed to verify if it is watertight. Install no additional pipe until first test section has passed the aforesaid tests. For line test sections that contain valves, the Contractor must demonstrate that each valve can hold test pressure.
Furnish the following equipment and materials for tests, unless otherwise directed by the Engineer:
1. Two (2): Graduated containers
2. Two (2): Pressure gauges, with maximum five (5) psi increments
3. One (1): Suitable pump, hose, and suction pipe as required
B. Testing Procedure: Test each 1,000 feet of line installed while trench is partially backfilled and joints are left exposed for examination for leaks. Do not conduct pressure tests until 48 hours after placement of concrete thrust blocks. After the pipe has been partially backfilled, slowly let water into the line. Vent to allow air in the line to be released. Flush the line as necessary for cleaning. Leave water in the line for 24 hours prior to pressure test. Test at 1 1/2 times working pressure or a maximum of 250 psi, calculated for low point of test section with a minimum of 150 psi or a maximum of 250 psi. The test pressure must be maintained within plus or minus five (5) psi during the entire testing period. Valve off the pump and hold pressure in the line for test. Test for two (2) hours or as agreed to by the District.
6.24 ACCEPTANCE AND RELEASE FOR TAPS
A new main shall be accepted by the District and released for taps when the following conditions have been met:
A. The main and all appurtenances thereto have been installed to the satisfaction of the District and all pertinent notes and measurements have been made.
B. Disinfection has been completed and the main has been flushed and charged.
C. Hydrostatic testing has been completed, witnessed, and approved by the District.
CHAPTER 7 - SPECIFICATIONS FOR BOOSTER PUMP STATIONS
The size, location, and type of booster pump station facilities shall be subject to inspection and approval by the District. For the sake of conformity, every effort shall be made to provide facilities that are consistent with the present District guidelines. Certain specific requirements must be met for booster pump station acceptance. These consist of:
A. All booster pump station installations shall have three-phase, 480-volt power supplies.
B. Minimums of two (2) pumps are to be installed. The pump station "firm" pumping capacity must be provided with the largest pump out of service. It is desirable to have the pumps all supplied by a single manufacturer. Pumps are to be provided with mechanical seals. Pumps are to be provided with an inlet and outlet isolation valve and a discharge check valve. Pump discharge control valves may also be required depending on the application as determined by the Engineer.
C. Fused disconnects are required outside the vault where all power to the vault can be secured and locked out. All electrical components must be approved by the District prior to installation.
D. Clearly labeled individual breakers inside the vault for each pump.
E. Hour meters for each pump capable of an analog signal, output signal adaptation to be transmitted to the computer at the Avon Drinking Water Facility (ADWF).
F. Flow meter to read gallons per minute and record total gallons produced. This must be capable of 4-20 milliamp signal adaptation to the Authority facility computer. Rosemont Magnetic Flow Meter shall manufacture the meter.
G. Suction and discharge pressure gauges with a digital/dial indicator capable of 4-20 milliamp signal to the ADWF computer.
H. Positive ventilation: The fans shall be mounted so as to exhaust air as near the capsule roof as practical. The fan's capacity shall provide adequate CFMs to produce one (1) air change every three (3) minutes. The ventilation system shall have its own 15-amp breaker and shall start with a signal generated when the hatch opens.
I. Pump station firm capacity shall be designed to provide complete filling of the service area tank within a time frame no greater than 24 hours under the expected build out maximum day demand.
J. Locking hatch with intrusion alarm. The intrusion alarm must be capable of transmitting a digital output (open/close contact switch) signal to the ADWF computer. Locking hatch must be rated for corrosive environment.
K. Adequate lighting: Fluorescent lighting with heavy gauge, all steel housing. Positive locking stainless-steel framed and gasketed enclosure.
L. Heater: Heavy gauge steel housing and extruded aluminum frame. Must run off thermostat and provide a heat range of 55 to 85 degrees Fahrenheit.
M. Dehumidifier: Unit to have dial controlled adjustable humidistat to automatically turn unit on or off at pre-selected moisture levels.
N. Wet Floor Alarm: Must be capable of digital output (open/close contact switch) signal transmission to computer at the ADWF.
O. Surge Relief Valve: Pilot controlled hydraulically operated, as manufactured by CLA-VAL.
P. An all aluminum access ladder will be provided. The ladder will meet UL and OSHA approval under Type 1, heavy-duty specifications.
Q. Lightning Arrestor: These shall be motor savers adequately sized to the pump motors.
R. Equipment Operation and Maintenance Manual: Three (3) copies are required.
S. Station vault shall contain a minimum of two (2) sump holes at opposite ends of the vault.
T. For the purpose of various temporary emergency bypass pumping, the District will require a fire hydrant at both the discharge and intake side of the booster pump station. Both fire hydrant installations must be within 20 feet of the booster pump station.
U. All electrical wiring must be properly labeled and identified (wire numbers with related schematic drawings.)
The Manufacturer shall also be responsible for installing the proper interface paneling and Unistrut to accommodate telemetry installation. Coordination of telemetry installations and interfacing shall be accomplished through a joint effort between the Manufacturer, Engineer, District personnel, and the Telemetry Contractor.
7.02 CORROSION PROTECTION
A. The steel structure shall be sandblasted after welding is complete and the prime coating operation shall take place immediately after surface preparation. The prime coat will be durable, chemical resistant, and shall be followed by two (2) applications of finishing enamel.
B. The manufacturer shall provide packaged magnesium anodes for cathodic protection. The anodes shall be buried equally spaced around the station and be connected by heavy copper wire.
C. All corrosion protection devices will follow NACE guidelines.
D. The ohmage of each anode ground bed will not exceed 30 ohm each, with current flow limited to that required for cathodic protection.
7.03 FINAL GRADE AND LANDSCAPING
A. Elevation to top of station hatch shall be 12-inches above finished landscaping. Landscaping shall slope away from the booster pump station.
B. Landscaping vegetation shall not interfere with entrance and egress of the booster pump station.
C. Landscaping sprinkler heads shall be directed away from vault.
CHAPTER 8 - BOOSTER PUMP STATION TELEMETRY
8.01 TELEMETRY CONTROL SYSTEM
A. Discharge control of the pump operation shall be accomplished by telemetry transmission via 4-20 milliamp signal. The telemetry system shall have the following capabilities:
1. Complete pump control
a. Start and stop pumps automatically based on predetermined tank set points.
b. Start and stop pumps by operator action.
c. A start/stop signal generation indication on the computer screen.
d. An override stop control for all pumps, based on a high tank level mechanical float device.
2. Pump status indication:
a. Green for pump running status.
b. Red for pump off status.
3. Full interface with field equipment capable of:
a. Flow meter readings
b. Flow totalizer readings
c. Pressure (suction & discharge) readings
d. Hour meter readings
e. Intrusion alarm
f. Wet floor alarm
g. Pump fault alarms
8.02 DATA INTERFACE MODEMS
A. There shall be included with each telemetry loop a pair of solid-state interface modems. One modem shall be set up to transmit only and the other to receive only. Each modem shall be complete with status lamps that continually monitor interface and controls circuits and are used in problem isolation.
The modems will be completed to the following specifications:
1. Adjustable transmit level maximum 0 db-15 db in 1-db steps.
2. Receive signal range 0 db-30 db.
3. External power requirements 120-volt nominal, 60 Hz., 7 watts.
4. Stand-alone enclosure.
5. Transmitter to accept isolated contact closure input.
6. Receiver to generate 12-vdc nominal at 60-ma current in response to contact closure at transmitter.
7. Modulation to be frequency shift-keyed type.
8. Solid-state construction using large-scale integrated circuitry.
9. Front panel push buttons for on site testing. Capable of self-test to determine if individual unit is functional. Capable of line-loop test to determine if line facilities are functional.
B. The booster pump station manufacturer shall furnish the booster pump station's telemetry system. It will be the manufacturer's responsibility to integrate the booster pump station hydraulic controls with the telemetry controls and produce a completely acceptable system.
CHAPTER 9 - CONSTRUCTION ACCEPTANCE
A. Field Maintenance Inspections
1. High Chlorine Test
See District Specification.
2. Low Chlorine Test
See District Specification.
3. Bacteriological Test
See District Specification.
4. Hydrostatic Pressure Test
See District Specification.
5. Valve Boxes/Curb Stops (To Grade and Operated)
All valves shall be free of dirt, rocks, and debris. Valve box segments must be straight and plumb, centered over the operating nut. See District Specification.
6. Fire Hydrant (To Grade and Operated)
The fire hydrant shall be straight and plumb, and shall be operated with proper drainage. See Fire Hydrant Assembly detail.
7. Air/Vacuum Release Valves
The District shall inspect the air/vacuum release valves.
8. Pressure Reducing Valve Inspection (PRV)
The PRV shall be inspected and set by the manufacturer.
9. Rough Grade Inspection
Above-ground attributes are to be in a reasonable grade so as not to allow standing water to accumulate on top of or allow drainage into the attributes of the system. All attributes within the road right-of-way/ easement shall be protected from traffic, equipment, etc.
10. Warranty Period
During the 2-year warranty period that begins at Construction Acceptance, the District will test the integrity of the telemetry and cathodic protection systems. Remedial repair and subsequent testing will be made by the applicant.
11. Redline Submittal
A redline submittal will be required to be made from the contractor to the engineer in order to facilitate the completion of as-builts in a timely manner.
B. Water Operations Inspections
1. Tank Inspections
a. Disinfection (ANSI/AWWA C652-92)
b. Fire hydrant installed near tank
c. Vents: Screened and secure
d. Overflow Drainage: Adequate
e. Hatches/Doors/Ladders: Secure
f. Installation of intrusion alarms
2. Pumps, Controls, Telemetry Inspections, and Testing
Prior to preliminary acceptance of each installation, a 48-hour on-line test will be conducted on the control/mechanical systems installed. It will be the responsibility of the applicant to prove the validity of all control and mechanical systems installed during the test period.
CHAPTER 10 - FINAL ACCEPTANCE
The following items shall be required to be submitted to the District for approval prior to Final Acceptance. Once these items have been received, reviewed, and approved by the District, Final Acceptance may occur.
A. Final Grade and Paving Inspection
All system attributes shall be fully operational and meet District Standards. Back lot access shall meet District Standards. The ring and cover shall be centered over the cone section. All system attributes shall meet or exceed District Standards.
B. Drawings of Record
Field measured Drawings of Record shall be submitted to the District in the specific format as required by the District. See Drawing Specifications detail. The Drawings of Record shall include, but not be limited to, all attribute information including main lengths, all bends (horizontal and vertical), valves, hydrants, materials, pipe diameters, encasement, insulation, pipe deflections, and service line information which shall include size, location of line, tap and curb stop. Water and Sewer Drawings of Record shall be submitted on the same drawing. The submittal will contain the swing ties for service lines. The District requires a digital format using District formatting (AutoCAD Release 14 or newer), and three (3) blue line copies of the field-measured Drawings of Record. The Drawings of Record shall also depict the established easement for each line segment with reference to the specific Eagle County recording information. Construction drawings will not be accepted as Drawings of Record.
C. Easement Documents
The District's standard Water Easement Deed form shall be completely filled out, notarized, and submitted to the District at the same time as the drawings of record submittal. The District shall require easement documentation to demonstrate that the constructed water main has been field verified to be within the proposed easement. Additionally, the documentation shall also show the proposed easement meets the minimum requirements for main lines as set forth in Section 3.06-A. The District shall require a professional land surveyor, registered in the State of Colorado, to submit a stamped survey of the easement(s), as well as the digital format. Each line segment shall be constructed within a recorded easement. The specific Eagle County Recording information shall be provided to the District. Please refer to the document form contained within these Specifications.
D. Operation & Maintenance Manuals
A complete Operation & Maintenance Manual must be submitted to the District for pump stations and telemetry systems. These manuals must also include electrical and control schematics for the equipment provided. Two (2) preliminary copies are to be submitted to the District for review and comments prior to equipment start up. Three (3) copies of the final hard cover bound manuals, incorporating any District review comments, are to be submitted to the District prior to final acceptance.
E. Project Cost
A copy of the contract to install the main line is requested.
F. Bill of Sale - Water Main
The District's standard Water Bill of Sale form shall be completely filled out, notarized, and submitted to meet this requirement. An exhibit depicting the main line shall also be required upon submittal. Please refer to the document form contained within these specifications. Prior to the expiration of the two-year warranty period, the District will re-sound the main line. This sounding inspection of the main will be at the District's expense. The purpose of this inspection is to determine if the line is still is still in good condition and free from debris. If the inspection reveals any defects, failures or debris, the Developer shall be required to correct, modify or remove the specific problem to the satisfaction of the District. The cost of this corrective action will be borne by the Developer. Once the corrective action has been completed the District will re-sound the line segment at the Developer's expense.
G. Final Inspection
The District shall perform a final walk through inspection prior to Final Acceptance. The purpose of this inspection is to determine if any changes have occurred since the final grade and paving inspection that would negatively effect the operation of the system. The owner or the owner's designated representative is required to accompany the District's Inspector during this final inspection.
STANDARD FORMS FOR WATER MAINS
-BILL OF SALE/DISTRICT
STANDARD DETAILS FOR WATER MAINS (click on detail to view)
-MAIN LINE PRESSURE REDUCING VALVE VAULT (TOP VIEW)
-MAIN LINE PRESSURE REDUCING VALVE VAULT (SIDE VIEW)