Appendix D - Standard Specifications for Sewer Main Construction
EFFECTIVE: JANUARY 2006
CHAPTER 1 - GENERAL REQUIREMENTS:
The Standard Specifications for Sewer Lines (the "Specifications") are promulgated by the Eagle River Water & Sanitation District ("District"). The interpretation and enforcement of the Specifications is hereby delegated to the District Regulations Administrator.
1.02 EFFECTIVE DATE OF SPECIFICATIONS
The Specifications shall be in effect immediately upon formal adoption by the District and shall supersede all former Specifications for sewer 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 sewer 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 connection shall only exist from the tap on the main to the property line.
D. 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 which has been damaged prior to the approval.
E. Collection System: Sewer mains together with all appurtenances including manholes, cleanouts, taps, and associated materials, property and equipment collecting wastewater from customers, excluding service lines.
F. District: The Eagle River Water & Sanitation District.
G. District Engineer: The authorized representatives of the District acting within the scope of the particular duties entrusted to them.
H. District Inspector: Authorized representatives of the District acting within the scope of the particular duties entrusted to them.
I. District Main: Mains eight inches (8") or greater which have been formally accepted by the District.
J. Electronic Drawing File: AutoCAD or equivalent computer design software digital submission meeting the design requirements of the District.
K. Main Extension: Extension to the existing sewer collection system located within the District.
L. Regulations Administrator: The authorized representative of the District who acts within the scope of the particular duties entrusted to that position.
M. Service Line: In the context of these specifications, the sewer line extending from the District's sewer main to the property line, including the connection (wye or saddle) to the sewer main. Service lines are not the responsibility of the District.
N. Shop Drawings: All drawings, diagrams, illustrations, brochures and other data which are specifically prepared by a 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.
O. 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 Sewer Lines 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 water and wastewater mainline extensions, replacements, modifications, reconfigurations, expansions of capacity, or abandonments as a result of development within the Eagle River Water & Sanitation District service area shall be made at the expense of the Developer or Applicant. The Developer or Applicant shall locate, survey, pothole, and/or videotape at its expense, any existing water or wastewater mainlines and facilities that may potentially be affected by construction prior to construction so as to avoid any potential conflict that may arise during or after construction. No work shall commence without the District’s written construction plan approval.
2.02 APPLICATION PROCEDURE
All inquiries, applications and submissions 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 plans.
The engineering design and 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 the proposed requirement for:
1. Points of connection to existing facilities with specific District attribute nomenclature.
2. Size of sewer mains to be installed.
3. Location of sewer mains to be installed.
4. Special features such as manholes, cleanouts, services, etc.
The Applicant shall submit final plans that have been prepared by and stamped by a Colorado Professional Engineer to the District for its review.
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 Sewer Mains. The Specifications take precedence over the District's plan review. The District is not responsible for omissions that occur during plan review.
2.03 SUBMISSION REQUIREMENTS FOR SYSTEM EXTENSIONS
Detailed plans for system 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.
The design and installation of all facilities shall ensure development of an integrated collection system. No work shall commence on any facilities until the District approves the plans for construction in writing and three (3) copies of the approved plan (1 wet-stamped) are submitted to the Regulations Administrator's office.
When a main is to be installed outside 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.
All proposed mains to be installed within a dedicated line easement or right-of-way will require plan drawings to be prepared by the Applicant's engineer and must be approved by the District.
Construction Plan Approval will not be granted without the issuance of an Ability to Serve letter, if required.
All final plans shall contain, but not be 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 and/or proposed utilities that may conflict with line installations and shall include size, type, and location.
5. The proposed alignment and size of the lines including the location of all proposed facilities such as manholes, cleanouts, services, etc.
B. Additionally, All Plans Shall:
1. Be based on actual field surveys referenced to 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, tapping and control.
2. Conform to a scale of one-inch (1") equals 100 feet 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) 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. In the event that said construction does not commence within nine (9) 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 nine (9) months, plans must be resubmitted for review and approval prior to commencement.
C. The Applicant shall secure and pay for all licenses and permits required for the main line extension.
D. 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.
E. The Applicant shall be responsible for the mains to be tested, cleaned, and televised. The District Inspector shall be notified in writing as soon as the mains have been tested, cleaned, and televised.
A. New installation, replacement, or repair of any existing facilities in the District's collection system shall be inspected and approved by a District Inspector. All lines shall be tested, cleaned and televised at the Applicant's expense. Cleaned shall mean, "free of any and all debris."
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 Specifications is achieved.
All appropriate permits and approved sewer 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 Conveyance Agreement form to the Applicant. The Applicant shall complete the form and return it to the District for final approval. A copy of the final approved form will 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.
Warranty period shall not expire until the final inspection has occurred and the Drawings of Record and recorded easement documents has been received and approved by the District.
2.07 SPECIAL CONDITIONS
When applying for a main extension, special conditions that involve another agency (e.g. Colorado Department of Transportation, Eagle County, etc.) may exist. All conditions of the other 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.
An approved traffic control plan 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 manholes and related appurtenances including service lines and locations. Additionally, sewer service stubouts shall be located by a minimum of three (3) "swing ties" off permanent landmarks (does not include property pins) per service. 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 a computer disk using the District's computer format (AutoCAD Release 14 or newer) and nomenclature. See Mapping Specifications detail.
2.09 MAIN LINE TESTING
Immediately after main line installation, the Contractor will conduct a vacuum and/or a pressure test on all manholes in specifically designated "wet areas". The Design Engineer and/or the District shall determine wet areas. Additionally, a pressure test of the main line will be required to insure that the main line is not leaking. 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 line. The District shall witness the testing.
The specific tests required by the District are listed on the "Sewer System Acceptance Procedure Form." of these specifications.
Before the end of the TWO-YEAR (2) warranty period, the District will re-televise the sewer main, at its own cost, to ensure its condition and integrity. If it is discovered that the main line is defective, it will be the responsibility of the Applicant to perform all necessary cleaning (construction debris, etc.), repairs, and re-televise the main. The repair will be inspected and approved by District personnel. The District will witness the re-televising of the main.
CHAPTER 3 - COLLECTION 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. Plans submitted will 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 SIZING COLLECTION MAIN
All mains shall be of sufficient size so as to collect wastewater from the area requesting service to the District wastewater treatment. All mains shall be a minimum eight inches (8") in diameter.
The District reserves the right to require over-size mains to provide service for projected future needs. The additional cost for the oversize may be negotiated between the District and the Applicant.
3.03 DESIGN CAPACITY AND DESIGN FLOW
In general, capacities are to be designed for the estimated ultimate tributary population, except in considering parts of the system that can be readily increased in capacity. Similarly, consideration is to be given to the maximum anticipated capacity of institutions, industrial parks, etc. Lift stations are specifically discouraged. Lift stations may only be installed with written permission from the District. Permission must occur prior to construction plan approval.
3.04 LAYOUT OF THE COLLECTION SYSTEM
A. Easement Width Requirements for Main Installations
All mains shall be installed in dedicated public streets. If it is not possible or feasible for such an installation to be made in a dedicated street, the installation shall be made in a right-of-way or easement. The minimum width of a right-of-way or easement that will be accepted by the District is 20 feet. The main shall be generally centered within the easement. Sufficient easement widths should be created to accommodate future excavation and maintenance requirements. If, at the determination of the District, it is not feasible to meet the above requirements, installations may be made in streets, right-of-ways, or easements of other widths when authorized by the Regulations Administrator. Easements shall be established at a minimum width of a one to one slope, (1:1) with a three-foot (3') base. Easement widths shall be rounded up to the nearest five-foot (5') increment. The vertical measurement to determine the easement width shall be from finished grade to the top of bedding. See Table 3-1.
|Sewer Pipe Cover Depth||
Minimim Easement Width Required (main shall be centered in easement)
|4'6" to 8'6"||20'|
|8'7" to 11'0"||25'|
|11'1" to 13"6"||30'|
|13'7" to 16'0"*||35'|
|16'1" to 18'6"*||40'|
|18'7" tp 21'0"*||45'|
*Manholes installed at a depth greater than 14-feet (14') will require alternatives analysis.
B. Minimum Size
All sewer main lines shall be a minimum of eight inches (8") in diameter. All sewer service lines shall be a minimum of four inches (4") in diameter.
C. Depth of Bury
In general, mains are to be sufficiently deep enough to receive wastewater from basements and to prevent freezing. The minimum cover above a main shall be four feet and six inches (4'6"). All main installations are to be checked to insure that pipe materials are suitable for the depth of excavation and backfill involved. The District reserves the right to have the Applicant verify that the materials being used are suitable for the proposed installation. Any proposed depth greater than 20 feet (20') will require District approval. In these deep main line installations a thicker walled pipe such as SDR-26 is required.
The maximum recommended depth for a sewer manhole is fourteen feet (14') (measured from the rim to bottom of the invert out). Any proposed applications with installation of manholes at a depth greater than fourteen feet (14') shall require an alternatives analysis and District approval.
D. 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 sewer line. Encroachments into easements are discouraged and shall only be allowed by written authorization from the District.
Buoyancy of mains shall be considered and floatation of the pipe shall be prevented with appropriate construction where high groundwater conditions are anticipated.
F. Required Minimum Slopes
All mains shall be designed and constructed to give mean velocities, when flowing full, of not less than two feet (2') per second, based on Manning's formula using an "n" value of 0.013. The following are the required minimum slopes that are to be provided; however, slopes greater than these are desirable. If a minimum slope is proposed, the District recommends the use of a heavier pipe thickness than SDR-35.
|Sewer Size||Minimum Slope in Feet (per 100 feet)|
* For 8-inch diameter mains, the District will require velocity analysis on distal lines for pipe slopes less than 0.70.
G. Slope Between Manholes
Mains shall be installed with uniform slope between manholes.
H. Steep Slope Applications
Steep slope applications in lines longer than 100 feet (100') in length or longer are required to install a bar screen manhole at the top and an energy dissipater manhole at the bottom. Mains at slopes of 20 percent (20%) or greater shall be anchored securely and installed with restrained joint connections. Clay dam barriers shall also be required every 300 feet or as required by the District. The first clay dam shall be installed prior to the grade break. Drainage from the uphill side of clay dams shall be day-lighted to a natural drainage course. Native materials screened at 1 1/2 inches (1.5") minus may be used in these applications with the approval of a variance request. A geo-technical engineer with the approval of the District shall make the determination of the use of native materials. Native materials shall not be used as bedding materials prior to approval by both a geo-technical engineer and the District. Mains installed at a greater than 20 percent (20%) slope (but less than 100 feet in length) will not have to adhere to steep slope protection requirements.
Curvilinear alignment of mains constructed with Yelomine pipe may be considered on a case-by-case basis providing the specific pipe manufacturers maximum allowable pipe joint deflection limits are not exceeded. Ten-gauge (10) insulated tracer wire is to be utilized in all such installations.
Manholes and Cleanouts:
Where Yelomine pipe is used, a bar screen manhole shall be placed at the top of each section with an energy dissipater manhole at the bottom. In place of manholes for Yelomine pipe, clean-outs shall be installed every 200 feet (200'). Clean out caps shall be installed with non-permanent gaskets
I. Groundwater Barriers
Groundwater barriers may be required in all areas where groundwater is encountered based on the Engineer's recommendation.
J. Slope Across Manholes
The minimum fall across a standard manhole is to be two-tenths of a foot (0.2').
K. Main Line Distance Measurement
Main line distances shall be measured horizontally, from the center of manhole to the center of manhole. To clarify, the center of the manhole lid is not the center of the manhole. Main line slopes shall be calculated from the outside invert of the manhole to the outside invert of the manhole. These distance and slope calculations shall be used for construction submittals as well as for the Drawings of Record submittal.
L. Manhole Connections
Any new main line connection, eight inch or greater, within a manhole shall match the crown of pipe to crown of pipe at the highest existing main currently within the manhole.
M. Location Tape
All lines connected to District mains in any way shall be marked with the appropriate tape to be placed 24 inches (24") above the highest point of said lines.
N. Pipe Material
The District will require that piping material of one consistent type be installed from manhole to manhole as couplings do not provide a smooth transition from one type of pipe to another contributing to solids accumulation. In those areas where encasement is required and include the use of C900 or Yelomine pipe, the length of line will be required to be C900 or Yelomine pipe from manhole to manhole, regardless of the length of the encasement.
All mains shall be installed with straight alignment between manholes. Straight alignment shall be checked by using either a laser beam or lamping.
Manholes shall be installed:
1. At the end of each line
2. At all changes in grade, size, or alignment
3. At all intersections
4. At distances not greater than four-hundred feet (400')
5. At minimum 10-feet from domestic water infrastructures.
Dead-end and main line manholes shall be provided with the access as shown on the Standard Details. See the details in the Specifications for additional information.
B. Drop Type
The use of drop manholes is discouraged. Drop manholes may be considered on a case-by-case basis. Drop manholes may only be installed with written authorization from the District. See the details in the Specifications for additional information.
The minimum diameter of manholes shall be 48 inches (48"); larger diameters are required for large diameter mains. A minimum access diameter of 24 inches (24") is required. For all pipe diameters up to and including 18 inches (18"), a four-foot (4') diameter manhole is required. For pipe diameters of 21 inches (21") through 27 inches (27"), a five-foot (5') diameter manhole is required and for pipe diameters of 30 inches (30") and above, a six-foot (6') diameter manhole is required.
D. Flow Channel
The flow channel straight through a manhole should be made to conform as closely as possible in shape and slope to that of the connecting mains. The channel walls should be formed or shaped to the full height of the crown of the outlet main in such a manner as to not obstruct maintenance, inspection or flow in the sewers.
E. Water Tightness
Manholes are to be constructed of precast concrete. Manhole lift holes and grade adjustment rings shall be sealed with non-shrinking mortar, bituthane wrap or such other material approved by the District. Manhole testing shall be required in "wet areas."
F. Manhole Covers
Cast iron manhole rings and covers shall be required in all manhole installations. Manhole covers shall have 22 and 1/8th inches (22 1/8") in diameter clearance, stamped SEWER and shall meet the AASHTO standard of HS-20. Any manhole lid not meeting these criteria shall be rejected.
G. Flat Lid Slabs vs. Cone Sections
Flat lid slabs are required to be installed on manholes with a depth of less than five feet (5') and must be eccentric. For any manhole greater than five feet (5'), flat lid slabs are prohibited from being installed on barrel sections in sanitary sewer applications.
H. Manhole Base
The base shall be precast unless it ties into an existing line.
I. Energy Dissipating Manholes
The bottom manhole on any sewer main which is 100 feet (100') or greater in length and has a slope of 20% or greater will require the installation of an energy dissipating manhole.
J. Bar Screen Manholes
The top manhole on any sewer main which is 100 feet (100') or greater in length and has a slope of 20% or greater will require the installation of a bar screen manhole
K. Manhole Steps
Manhole steps must be vertically aligned and plumb. Steps installed into any manhole must meet District standards for type of step as well as distance from the ring and cover to the first step. The District will not allow the steps to be installed in the "chimney" portion of the manhole. Entry steps are to be located in the barrel and cone sections of the manhole. See Standard Manhole Detail.
3.07 PROTECTION OF EXISTING SEWER SYSTEM
On the outlet of the connection point to the existing District sewer main, a mechanical plug shall be installed to prevent any flow, debris and or material from the newly constructed main line from entering the District's system. The plug shall be normally set on the downstream out line of the manhole. Plugs shall be installed per the direction of the District's Inspector. The plug shall be a mechanical-type device and is to be secured to the existing manhole to prevent loss of plug.
The plug shall not be removed until Construction Acceptance has occurred.
The Contractor shall be required to make routine inspections of the mechanical plug to insure that no leaking is occurring. If a leak is found, the Contractor shall immediately notify the District and take corrective action.
3.08 PROTECTION OF WATER SUPPLIES
When wastewater mains are proposed near any water supply facilities, including water service lines, requirements of the Colorado Department of Public Health and Environment (CDPHE) are to be followed to confirm acceptable isolation distances in addition to the following requirements. The District acknowledges that these may be more restrictive conditions than the State of Colorado's requirements.
A. Cross Connections Prohibited
There shall be no physical connections between a public or private potable water supply system and a main or appurtenance thereto which would permit the passage of any wastewater or polluted water into the potable supply. No water pipe shall pass through or come into contact with any part of a sewer main or manhole.
B. Relation to Water Works Structures
While no general statement can be made to cover all conditions, it is generally recognized that mains shall meet the requirements of the appropriate reviewing agency with respect to minimum distances from public water supply wells or other water supply sources and structures.
3.09 RELATION TO WATER MAINS
A. Horizontal and Vertical Separation
Mains and sewer service lines shall be installed at least ten feet (10') horizontally from any existing or proposed water main. The distance shall be measured edge to edge. In cases where it is not practical to maintain a ten-foot (10') separation, the District may allow installation of the sewer main closer to a water main with a District approved variance utilizing required encasement, provided that the water main is on a separate trench or on an undisturbed earth shelf located on one side of the main and at an elevation so the bottom of the water main is at least 18" inches (18") above the top of the sewer main. The District requires a 10-foot (10') separation between water and sewer attributes including manholes. This separation will be measured from outside pipe to outside pipe. If a manhole is installed, it will be measured from outside of manhole to outside of water attribute.
If water line is 18 inches (18") or less above the sewer main or if water line is below the sewer main line, C-900 PVC pressure pipe or Yelomine pressure pipe shall be used in the installation of the sewer line from manhole to manhole.
A Harco adapter coupling is to be used with transitions from and to SDR-35 and C-900 as specified.
CHAPTER 4 - MATERIAL SPECIFICATIONS
4.01 MATERIALS AND TESTING
All materials must conform to the Material 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 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 that meet the requirements of the Specifications.
4.02 PIPE PRESSURE CLASSES
The District has established minimum design safety factors for system piping. The following minimum AWWA and ASTM pressure classes for acceptable types of pipe are required:
- Ductile Iron Pipe (DIP) - Class 350 (AWWA C151)
- Polyvinyl Chloride (PVC) - Non-pressured pipe SDR-35
- Polyvinyl Chloride (PVC) - Yelomine - Pressure pipe SDR-21
- Polyvinyl Chloride (PVC) - C-900 Pressure pipe
4.03 PIPE AND FITTINGS
A. Polyvinyl Chloride (PVC): 4 to 15 inches (4" to 15"), ASTM D3034, Type PSM, SDR-35; 18 to 27 inches (18" to 27"), ASTM F679 for push-on joints and molded rubber gaskets. Maximum pipe length 20 feet (20").
B. Ductile Iron: AWWA C151, Class 350. Push-on joints. Poly-lined or Griffin "SewperCoat" ASTM A746.
C. Yelomine: SDR-21, Restrained joint PVC pressure pipe and fittings. Conform to ASTM D2241 "Standard Specifications for PVC, pressure rated pipe (SDR Series)."
D. Polyvinyl Chloride Pipe and Couplings: AWWA C-900, working pressure 200 psi, with push-on joints ASTM D1869, Class 150, and ASTM 3139. All spigot ends shall be beveled to manufacturer's specifications.
E. Only GENCO Saddles may be used in conjunction with C900 or Yelomine Pipe. Factory wyes will be used in conjunction with SDR 35 pipe.
A. Manhole bases: Precast concrete, ASTM C478.
B. Manhole Sections: ASTM C478. Precast concrete (wetcast) with the lip outside, low end down. Cones shall be eccentric.
C. Manhole Rings and Covers: Cast iron, ASTM A48 with a flat lid with the lettering "SEWER" cast on the cover. Ring and cover combined weight is to be greater than 255 pounds and machined to fit securely with a non-rocking cover. Waffle pattern hot dipped in asphalt. HS-20 traffic loading. D&L A1043 or accepted equal.
D. Manhole Grade Rings: Precision Cover Systems, Inc. (PCSI) fully-adjustable manhole covers with variable grade rings that adjust to meet different roadway heights and grades will be installed where required by District.
E. Manhole Steps: Two non-skid grooves in surface of step and capable of a vertical load of 800 pounds and a pullout load of 1500 pounds (ASTM - C478), six inches (6") from face of manhole. The steps shall meet industry standards or equal and be plastic coated.
F. Manhole Joint Sealant: Double Rub-R-Nek with primer. One inch (1") on 48-inch diameter manholes; 1-1/2 inch on all larger sizes.
G. Hughes manhole products have been approved for installation.
4.05 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 1/2 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 and the use of screened rock is prohibited in these applications. See Sewer Pipe Bedding Detail (S-10).
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.
4.06 CONCRETE MATERIAL
A. General: All materials furnished from sources approved in writing by the District.
B. Cement: ASTM C-150 for Portland Cement, Type II. Cement, which 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.
4.07 CONCRETE MIX
A. Design Mix
a. Cement 5 1/2 sacks per cubic yard
b. Coarse aggregate - 43 percent (43%)
c. Water - 5 1/2 gallons per sack
d. Maximum size aggregate - 3/4 inch
2. Slump: 4 inch maximum
3. Strength: Minimum 3,000 psi at 28 days
4. Air Content: 5 percent - 7 percent (5 to 7%)
4.08 TRACER WIRE
Tracer wire shall be ten-gauge (10) insulated copper wire, and be required on all curve-linear applications.
4.09 LOCATING DISK
The District will provide 3M "Green" locating disks to the contractor. The contractor shall ensure their correct installation.
4.10 MARKING TAPE
The installation of "green" marking tape is required on all sewer mains and service lines. The tape shall be installed approximately 2 feet above the main or line. The tape shall meet the following specifications:
1. 4-mil thick PVC material.
2. Solid green color with black lettering.
3. Six inches (6") in width.
4.11 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 separation 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 feet (10') 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 an approved equal restrained joint device and Cascade Waterworks Manufacturing Company, Model CCM casing spacers.
CHAPTER 5 - EARTHWORK
5.01 EARTHWORK DEFINED
Earthwork shall include all 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 and pedestrians 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 entity including Eagle County, Colorado Department of Transportation (CDOT), Special Districts, the Town of (TOA), the Town of Minturn (TOM), or the Town of Vail (TOV) 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 underground utilities and structures, both known and unknown, may be determined. The Contractor shall be held responsible for the repair of such utilities and structures when broken or otherwise damaged because of negligence or carelessness on his 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 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 large stones shall be removed to provide a clearance of at least six inches (6") below and on each side of all pipes and manholes. 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 Shoring
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 facilities or items.
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 or obstruct traffic.
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, written authorization shall be obtained from the applicant of the property and a copy submitted to the District, prior to said disposition. 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 has been 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 points, 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.
Clay barriers may be required where groundwater is encountered, anticipated or by the direction of the Engineer. See Groundwater Barrier detail.
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.
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 compaction is to insure uniform support for the pipe.
The limits of pipe bedding shall be from a minimum of six inches (6") below the bottom of the pipe to 12 inches (12") above the top of the pipe. Approved backfill may then be installed to the ground line.
B. Bedding Material
The bedding material shall be clean and free from corrosive properties and shall conform to the gradation limits specified in Chapter 5, Material Specifications.
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, the 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, vegetation 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.
All trenches shall be backfilled with care, from the bottom of the trench to the centerline of the pipe with 3/4 inch, screened rock or other approved material placed and compacted. Backfilling 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 (12") 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 (12") above the pipe to the grade shown on the plans or as specified herein, the trench shall be backfilled by approved mechanical methods.
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 herein and the areas shall be left in a state of order and cleanliness. All cleanups shall be performed within ten (10) days or an acceptable schedule agreed upon by all parties involved. Cleanup shall be to the satisfaction of the District Inspector.
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 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, warping, or any 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
Manholes shall be installed at staked locations and elevations. Main installation stakes for alignment and grade shall be set by a Professional Land Surveyor who is registered in the State of Colorado.
Flat areas or low spots are not acceptable. The Developer shall submit videotape with cut sheets to the District for review. The District's review of the videotape shall determine any area for replacement or repair. The District's determination shall be final.
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 ten percent (10%) 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 BULKHEADS FOR ALL PIPE TYPES
A manufacturer's approved plug shall be used as a temporary plug during line installation. All temporary plugs shall be provided by the Contractor.
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, manholes, and accessories shall be carefully lowered into the trench piece by piece by means of ropes or other suitable tools or equipment, in such a manner as to prevent damage to the materials. Under no circumstances shall the materials be dropped or dumped into the trench.
If damage occurs to any pipe, manholes or 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 debris 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. The canvas bag shall be left in place until the connection is to be made to the adjacent pipe. During installation, 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 sewer main.
B. Ductile Iron Pipe
1. Push-On Joint
Immediately before joining two (2) lengths of ductile iron pipe, the inside of the bell, the outside of the spigot end, and rubber gasket shall be thoroughly cleaned to remove oil, grit, excess coating and other foreign matter. The rubber shall be flexed inward and inserted in the gasket recess of the bell socket. Since different manufactured brands of pipe require different types of gaskets, the Contractor shall exercise caution to ensure that the correct type of gasket is used.
A thin film of 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 assure 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 sections. However, if pipe is pushed home with a backhoe bucket, a wooden shield must be placed between the backhoe bucket 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 assure that the gasket is correctly aligned in the gasket recess of the bell socket and not twisted or turned.
C. Polyvinyl Chloride Pipe
1. Elastomeric Gasket Joint
Immediately before joining two (2) lengths of PVC pipe, the inside of the bell or coupling, the outside of the spigot and the elastomeric gasket shall be thoroughly cleaned to remove all foreign material.
Lubrication of the joint and rubber gasket shall be done in accordance with the pipe manufacturer's specifications.
Care shall be taken that only the correct elastomeric gasket, compatible with the annular groove of the bell, is used. Insertion of the elastomeric gasket in the annular groove of the bell or coupling must be in accordance with the manufacturer's recommendations.
The spigot and bell or coupling shall be aligned and pushed "home". Pushing the pipe "home" exceeds the manufacturers recommended reference line. Installation or pushing shall be done in a smooth, steady motion. Upon completion of joining the pipe, an inspection shall be made to assure that the gasket is correctly aligned in the gasket recess of the bell socket and not twisted or turned. NO deflection will be allowed at a joint of PVC pipe.
2. Pipe Storage
Pipe to be stored outside, and exposed to sunlight for more than thirty (30) days is to be covered with an opaque material such as canvas. Clear plastic sheets are not to be used to cover pipe. Air circulation will be provided under the covering.
3. Handling of Pipe in Cold Weather
PVC pipe has reduced flexibility and impact resistance as temperatures approach and drop below freezing. Extra care should be used in handling and installing PVC pipe during cold weather.
4. Tapping of C-900
Tapping of C-900 shall be made by use of a GENCO tapping saddle.
5. Tapping of SDR-35
Tapping of SDR-35 shall be made by use of a factory wye.
D. Yelomine Pipe
Installation of Yelomine pipe shall be in accordance with the manufacturer's recommendations and specifications. Cleanout caps shall be installed with non-permanent gaskets
E. Bedding of Pipe with Road Base or Approved Native Material
All bedding materials shall be compacted to District specifications. Compaction shall be made in two (2) lifts. The first lift shall be for the bottom of trench, the pipe shall be installed and then the final lift of bedding material shall be compacted to the spring line of the pipe. Compaction shall continue as per the Engineer's specification requirements.
F. Job-Mixed Concrete
Job-mixed concrete will be mixed in a drum mixer conforming to Concrete Paving Mixer Standards of Mixer Manufacturers Bureau of Associated General Contractors of America. The mixer shall be capable of combining aggregates, cement, and water into a thoroughly mixed and uniform mass. The entire contents of drum are to be discharged before recharging. The mixing of each batch will continue for not less than ten (10) minutes after all materials are in the drum.
G. Ready-Mixed Concrete
Said materials must be proportioned, mixed and transported in accordance with ASTM C94. Any concrete not plastic and workable when it reaches project shall be rejected.
H. Tracer Wire
Tracer wire shall be installed on all Yelomine pipe where changes in alignment may take place and/or where curvilinear pipe installations occur. The tracer wire shall be 10-gauge copper insulated wire.
I. Marking Tape
The installation of "green" marking tape is required on all sewer 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 green color with black lettering.
3. Six inches (6") in width.
Manholes shall be precast and constructed in accordance with the District's approved drawings. Precast manholes shall be designed so that all joints are waterproof. Precast manholes shall be made watertight 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. Poured in place manholes will only be allowed when connecting to an existing main.
6.13 SERVICE LINES
Service lines shall be placed true to line and grade in accordance with the construction drawings, from the main line to structure, in shortest direct route. All sewer service lines shall be located ten feet (10') minimum from all water lines. Stubouts shall be located five feet (5') from lowest corner of lot and terminated one foot (1') into the lot or as shown on drawings. Each wye shall be inspected prior to backfilling. Service line shall have a minimum grade of 1/4 inch per foot. If service line is to be stopped at property line, a 3M marker shall be installed four feet (4') deep at the termination of the stub and a watertight plug will be placed in end of service line. A six-foot (6') steel fence post, painted green, shall be placed at the end of the service line and shall extend four feet (4') above the ground. Refer to the Standard Detail for additional information.
A green 3M-stubout disk shall be installed by the Contractor/Applicant and shall be placed in accordance with the Specifications. The District shall provide the 3M disk. See Sewer Service Connection detail.
Cleanouts are recommended to be installed at bends in the service line or every 100 feet (100').
Connection of service lines directly to District manholes is allowed only with written District approval.
Stubout locations shall be triangulated from a minimum of three (3) permanent objects and described as such on the required Drawings of Record. Examples of permanent objects are property pins, manhole lids, transformers, water valve boxes, etc.
The District assumes no responsibility for the installation, inspection and/or compliance of sewer service lines to the recommended standards. Inspection performed by District personnel does not ensure that the installation meets District standards. It is the responsibility of the owner and his/her representatives to ensure that compliance is achieved.
6.14 CONNECTION TO THE SYSTEM
Connections to the District system shall be made in a neat and workmanlike manner. The connection shall be inspected and approved by the District prior to backfilling.
B. Tapping Existing Mains (After District Acceptance)
Application for service must be filed with the District on forms provided by the District and accompanied by appropriate fees prior to any action to connect to the system. Only upon authorized approval of the application and a receipt therefore, may a connection to the system be made. The District shall make all taps. A minimum separation of eighteen (18") shall be maintained between physical taps. All sewer taps / flow lines, shall be made 30 degrees above the spring line of the main. See Sewer Service Connection detail.
C. Connections to Manholes
All connections shall match the crown of pipe to crown of pipe at the highest existing main or per the direction of the District. All new main installations shall require reformed benches that meet all District standards.
It will be the responsibility of the Applicant to coordinate inspections with the District. Applicant shall contact the District 48 hours in advance to schedule inspections.
It will be the responsibility of the Applicant to clean and televise all main line installations and provide the original videotape with audio explanations and District format cut sheets to the District. The cut sheets shall be completely filled out prior to submittal to the District. The District shall charge an inspection fee for tapes that are unacceptable and will require a re-television of the main. The rate charge shall be in accordance with the District's hourly manpower fee.
E. Line Acceptance Procedure
A copy of the Sewer Line Acceptance Procedure and check-off list has been incorporated in the Standard Specifications for the Applicant/Contractor's review and compliance. Please refer to the Standard Forms for Sewer Lines.
6.15 EXFILTRATION / INFILTRATION TEST BY AIR
Each section of pipe between consecutive manholes shall be tested. Pressure-holding time is based on an average holding pressure of 3-psi gauge or a drop from 3.5-psi to 2.5-psi gauge. Additional air must be added until internal air pressure of sewer line is raised to approximately 4-psi gauge. After internal pressure of approximately 4 psi is obtained, allow time for air pressure to stabilize. Pressure will normally show some drop until temperature of air in test section stabilizes. When pressure has stabilized and is at or above starting test, pressure may be allowed to drop to 3.5 psi. Contractor must record the drop in pressure for test period. If pressure has dropped more than 1-psi gauge during the test, the service line has failed. Test may be discontinued when prescribed test time has been completed even though 1-psi drop has not occurred (ASTM C828 Low Pressure Air Test for Sanitary Sewer).
The time elapsed shall not be less than the following:
|Pipe Size (inches)||Time (minutes)|
6.16 MANHOLE TESTING
Specifically identified manholes shall be tested either hydrostatically or by vacuum test. The procedures to be followed for said tests are as follows:
A. Hydrostatic Pressure Test
1. Plug all inlets and outlets.
2. Fill manhole to top of cone section with water.
3. Allow water to stand for 24 hours.
4. Check leakage during the following 24-hour period.
5. The allowable leakage is any amount less than 0.2 gallons per vertical foot above the invert.
6. Repair all manholes that do not meet leakage test and retest.
B. Vacuum Test
1. Plug all inlets and outlets.
2. Install the vacuum tester head assembly on the manhole.
3. Attach the vacuum pump assembly to the proper connection on the test head assembly. Make sure the vacuum inlet/outlet valve is in the closed position.
4. Inflate the sealing element to twice the test pressure to be used. Do not over inflate.
5. Start the vacuum pump assembly engine and allow preset RPMs to stabilize.
6. Open the inlet/outlet ball valve and evacuate the manhole to ten-inch (10") Hg (mercury) that is equivalent to approximately 5 PSIG (0.3 bar) backpressure.
7. Close the vacuum inlet/outlet ball valve, disconnect the vacuum pump and monitor the vacuum for one (1) minute.
8. Allowable leakage - less than one-inch (1") Mercury (Hg) in one (1) minute.
9. All manholes that do not meet the minimum amount for the leakage rests must be repaired and re-tested.
6.17 TELEVISION TEST
A. The Contractor shall provide the District with a tape or disk of all television tapes tested with 3.5 gallons per minute of water flowing in VHS, CD, or WinCan format with an audio narrative of the inspection with all footage and locations noted on each tape. District standard cut sheets shall accompany each tape/submittal. The District prefers CD or WinCan format.
B. Mains shall be televised with water introduced into the main at the direction of the District's Inspector. Televising shall occur with the direction of flow unless prior written approval has been given by the District's Inspector.
C. Submitted tapes shall include:
1. Footage indicator
2. Running time
5. Beginning and ending manhole numbers for each run
District format cut sheets are required to be submitted in addition to the tape.
6.18 TELEVISION INSPECTION
Prior to construction/final acceptance of any sanitary sewer line by the District, said line shall be inspected internally by television as outlined in Sections 6.17 and 6.18. Defects such as high and low spots, joint separations, offset joints, chipped ends, cracked or damaged pipe, infiltration points and debris in lines shall be corrected by the Contractor. For joint separations, low spots and chipped ends. The following acceptable limits will apply.
- Joint separations: none (zero tolerance)
- Low spots: none (zero tolerance)
- Chipped ends: none (zero tolerance)
- Dimples or bumps in the pipe: none (zero tolerance)
A. The complete job is ready for television inspection when the following work has been completed.
1. All sewer pipelines are installed and backfilled.
2. All attributes are in place, all inverts are complete and pipelines are accessible.
3. All other underground facilities, utility piping and conduits are installed.
4. Pipelines to be inspected have been jet cleaned.
5. Final air test has been completed.
B. When the above work is complete, the Contractor shall arrange for the television inspection.
C. The Contractor of the project will notify the District in writing as to the scheduled date of the television inspection.
D. After conditions 1 through 5, as outlined above (A.), are met, the entire job will be initially televised. After conditions 1 through 5, as outlined above (A.), are met, the entire job will be initially televised.
1. A videotape will be made and defects requiring correction will be noted.
2. If no deficiencies are observed, the work will be considered satisfactory.
E. The Contractor will be notified in writing of any deficiencies revealed by the television inspection that require repair. If corrective work is indicated and the Contractor wishes to view videotapes, he shall contact the District to set a time for the viewing.
F. Corrective work shall be completed.
G. Those segments of the pipeline system that have been corrected must be re-televised.
H. The procedure outlined in conditions A through G above will be repeated until all deficiencies observed by television inspection have been corrected to the complete satisfaction of the District.
I. Prior to submittal to the District, the videotape shall be reviewed by the Engineer, Applicant, and Contractor for any defect that may be visible. If tapes and cut sheets are submitted to the District that are obviously "unacceptable," the Contractor shall be charged for the time taken by District personnel to review the tape. The minimum charge shall be one hundred dollars ($100).
6.19 SEWER MAIN REPAIRS
All proposed repairs must be approved by the District Inspector prior to actual repair. Once repair has been made, inspection will be required by a District Inspector. There will be no exception to this requirement.
If a repair and/or correction is made in a sewer line segment, the entire line segment shall be required to be re-televised with water flowing. A line segment is defined as the entire length of sewer line from manhole to manhole.
CHAPTER 7 - CONSTRUCTION ACCEPTANCE
A. Manhole Interior and Rough Grade Inspection
All steps within any manhole shall be plumb and in proper alignment. "Rub-R-Nek" all interior and exterior rings of the manhole sections. Ring and cover shall be centered with "Rub-R-Nek" between both. Inverts shall be grouted. No water shall be allowed to accumulate or stand in the flow channel or inverts. The flow channel and benches shall be free of all dirt and debris.
B. Air Test
All main line segments shall be air tested in according with District Standard Specifications.
C. Lines Jet Cleaned
All sewer main lines shall be "jet" cleaned.
All main lines segments shall be televised with District format cut sheets in accordance with District Standards Specifications.
E. Rough Grade Inspection
Above ground attributes are in a reasonable grade to not allow standing water to accumulate on top of or allow drainage into the sanitary sewer. All attributes within the road right-of-way/easement shall be protected from traffic, equipment, etc.
F. 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.
CHAPTER 8 - FINAL ACCEPTANCE
The following items shall 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
Manhole rings and covers shall meet the District's Standards relating to finish grade. Back lot manholes shall have adequate drainage. Backlot 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. Drawings of Record shall indicate all attribute information including main lengths, material, slope, manhole diameters, encasement, insulation, bends (steep slope applications only), invert and rim elevations, and service line information which shall include size, location of line, and cleanouts (if used). 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 shall require a digital submittal, and three (3) blue line copies of the field-measured Drawings of Record. The digital submittal shall be in AutoCAD (.dwg) format and may be delivered by means of compact disk (CD), 3.5" floppy disk, Zip Brand 100 MB or 250 MB disk, or e-mail. The Drawings of Record shall also depict the established easements 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 sewer "Easement Deed" form shall be completely filled out, notarized, and submitted to meet this requirement. Please refer to the document form contained within these specifications. The District shall require easement documentation to demonstrate that the constructed sewer 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 Chapter 3, Table 3-1 of these specifications. 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 Drawings of Record on AutoCAD disk in the format previously specified by the District. Each line segment shall be constructed within a recorded easement. The specific Eagle County Recording information shall be provided to the District.
D. Project Cost
A copy of the contract to install the main line is required.
E. Bill of Sale - Sewer Main
The District's standard sewer 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-televise the main line. This televised inspection of the main will be at the District's expense. The purpose of this inspection is to determine if the line meets District standards and is 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-televise the line segment at the Developer's expense.
F. Final Inspection
The District, prior to Final Acceptance shall perform a final walk through inspection. 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 will be required to accompany the District's Inspector during this inspection.
STANDARD FORMS FOR SEWER MAINS
STANDARD DETAILS FOR SEWER MAINS (Click on detail to view)