8-219 Section 823. Water Mains
823.01 Description
This work consists of excavating, installing, testing, disinfecting, and backfilling ductile iron water mains and appurtenances and providing as -built plans of the completed work . Other water main materials may be required by the contract.
823.02 Materials
Provide materials in accordance with the following sections : Pipe ....................................................................................................... 923 Water Services ...................................................................................... 923 Gate Wells ............................................................................................ 909 Gate Valves ........................................................................................... 923 Tapping Valves ...................................................................................... 923 Valve Boxes and Curb Boxes ................................................................ 923 Corporation Stops and Curb Stops ....................................................... 923 Service Saddles .................................................................................... 923 Fire Hydrants ........................................................................................ 923 Backfill Material ..................................................................................... 902 Polyethylene Encasement .................................................................... 923 Castings ................................................................................................ 908
823.03 Construction
Install pipe materials required by the contract in accordance with AWWA Standards.
A.General . The plans show the locations of existing utilities in accordance with available data. If the work requires precise information on the location of existing utilities, the Contractor will expose utilities shown on the plans to determine the actual locations. Do not disturb or cut into existing in-service water mains . If the operation of valves in existing water mains is required, notify the Engineer in advance so the Engineer may give the municipality 3 working days advance notice . Coordinate scheduling of water main connections with the municipalit y. Secure the Engineer’s approval of the schedule before beginning the work . The municipality is responsible for customer notifications. The municipality will open or close valves, as required to perform the work, without charge to the Contractor . In case of an emergency, the MDOT Standard Specifications for Construction Section 823 8-220 Contractor, with the approval of the Engineer, may operate valves to resolve the emergency. Minimize the out -of-service time for existing water mains . Make connections at night, on Sundays, or on holidays, as conditions require or as approved by the Engineer . Minimize interference with the water supply if abandoning existing water mains and incorporating new water mains into the water system.
B.Trench Excavation . Excavate water main trenches to the lines and grades shown on the plans in accordance with modifications approved by the Engineer or to meet or bypass existing utility structures . Excavate trenches to the depths shown on the plans to provide at least 5½ feet of cover from top of water main to the final grade. Excavate trenches to the widths shown on the MDOT Standard Plan R -83 series. Excavate the bottom of the trench to the required grade to allow 6 inches of bedding for the pipe. Do not block under the pipe. Maintain trenches for water mains free of ground or surface water by pumping or as otherwise approved by the Engineer. Install, and later remove, temporary timber bracing, as required to prevent movement or damage to new or existing water mains or adjacent utilities. During backfilling, carefully remove supports for sheeted and braced excavations to prevent earth banks or adjacent streets from collapsing. The Contractor may leave sheeting and bracing in place during backfilling and remove after completing backfilling operations . The Contractor may leave sheeting and bracing in place, if approved by the Engineer and the Contractor cuts it off 5 feet below the ground surface.
C.Disposal . Dispose of waste material as specified in section 205.
D.Laying the Pipe . Install the pipe joint restraint system in accordance with the manufacturer ’s recommendations . Assemble the pipe in the trench. If deflections at joints are required by changes in grade or alignment or to plumb valve stems, ensure that deflections of bell and spigot joints do not exceed the manufacturer’s recommendations . Ensu re that the deflection at the joints of mechanical joint fittings does not exceed three-quarters of the maximum deflection recommended by the joint manufacturer or that allowed by AWWA C600, whichever is less . Do not store or leave tools or other objects i n the pipe. Provide joint restraint at fittings and deflections of 11¼ degrees and larger . Provide joint restraint in accordance with the Joint Restraint Schedule shown on the plans. MDOT Standard Specifications for Construction Section 823 8-221 The Engineer may require thrust blocks in accordance with the municipalit y’s standards or if making connections to existing water mains. Construct thrust blocks to bear on undisturbed earth. Perform the work, including cold weather protection, in accordance with section 706. Relocate a portion of water main to avoid a conflict with another utility where proposed water main is not otherwise being installed in accordance with the w ater main conflict detail as shown on the plans . Disinfect and test as required. Install water main in casing pipe where called for on the plans using casing chocks or wooden skids for positioning of the carrier pipe. Use flowable fill with wooden skids as detailed on the plans. After placement of the carrier pipe, grout both ends of the casing with a mixture of Portland cement and sand in any propor tion that does not have more than 50% sand by volume. Ensure that the grout does not extend lengthwise into the casing more than 1 foot.
E.Abandoning Water Mains . Remove and dispose of abandoned pipe, gate boxes, or other appurtenances as necessary for place ment of a new water main at no additional cost to the Department . Remove portions of gate boxes to at least 3 feet below the pavement surface under the road and to at least 12 inches below the planned grade outside the road. If the Engineer determines that abandoned mains may remain in place, block the ends of the abandoned mains with concrete. If shown on the plans or as directed by the Engineer , fill abandoned water mains with non-structural flowable fill.
F.Valves. Set and join valves to the water mains as required for cleaning, laying, and jointing the required type of pipe, as shown on the plans . Install valves as required by the contract or as approved by the Engineer . Place the valve stems plumb . Install self -supporting valves that do not bear on the pi pe.
G.Live Taps. Hand-chlorinate tapping sleeves and gate valves before installation. Perform a wet tap into live water mains according to the manufacturer’s recommended procedures.
H.Live Stop . Install and operat e a water main line stop to isolate a secti on of existing live water main. Complete all work in accordance with the Standard Specifications as applicable. Determine the material, size, ovality , and condition of the existing water main prior to ordering the line stop materials. Verify that the pressure in the main is below 100 psig prior to installation of the line stop. MDOT Standard Specifications for Construction Section 823 8-222 Do not attempt to force, reshape, or bend saddle plates by excessive tightening of saddle studs. Utilize concrete supports and reaction bloc king for the line stop fitting per the municipality’s requirements as approved by the Engineer . Complete a pressure test after assembly of the line stop saddle, drain nozzle, and fitting. Remove the line stop and i nstall a completion plug and blind flange. Check for water tightness prior to abandonment of the line stop fitting. Coat the whole assembly with coal tar epoxy to a final minimum cured thickness of 0.020 inches.
I.Valve Boxes. Provide valve boxes that do not transmit shock or stress to the valve. Place valve boxes plumb over the operating nut of the valve, with the box cover flush with the pavement, or as approved by the Engineer . Provide firm support for valve boxes.
J.Adjusting and Reconstructing Water Shutoffs or Gate Boxes . Adjust and reconstruct w ater shutoffs or gate boxes to the final grade or as approved by the Engineer . Replace shutoff or gate box materials damaged during adjustment or reconstruction, as determined by the Engineer.
K.Water Services. Construct water services from the distribution main to the right -of-way line or as approved by the Engineer. Construct the service pipe with at least 5 feet of cover. Make all service connections and transfers . Maintain and protect, at no additional cost to the Department, existing service connections requiring transfer, but not shown on the plans, until reconnection or disposal. If relocating a portion of water service, shut down the water service by freezing or other method approved by the Engineer.
L.Gate Wells. Build gate wells as shown in the contract and in accordance with section 403. Mix mortar for masonry work in quantities that will be used before initial set . Do not use mortar that requires retempering. Position the valve nut to allow access through the opening in the manhole. Construct wells to allow minor valve repairs . Protect the valve and pipe from impact where passing through the well walls.
M.Water Mains, Cut and Plug . If the plans show cutting and plugging water mains, arrange for the municipality to shut down the main. Remove the section of pipe and plug the water main as shown on the plans or as approved by the Engineer . Construct the required thrust block and MDOT Standard Specifications for Construction Section 823 8-223 complete backfilling operations . This pay item does not apply to bulkheading abandoned pipe.
N.Fire Hydrants. Set fire hydrants at the locations shown on the plans or as coordinated with the municipality and directed by the Engineer . Equip the hydrant with auxiliary valves, as shown on the plans . Stand hydrants plumb with nozzles parallel or normal to the curb and wi th the pumper nozzle normal to the curb. Place the nozzles at the height specified by the manufacturer and at least 16 inches above the curb grade or as approved by the Engineer. Paint hydrants in accordance with the municipality’s standard requirements.
O.Fire Hydrant Removal . If the plans show removal of a fire hydrant, remove the entire hydrant assembly, including the following:
1.Auxiliary gate valve and box, unless approved otherwise by the Engineer;
2.Internal valve assembly;
3.Top bonnet;
4.Standpipe; and
5.Hydr ant inlet body if not encased in concrete. If the Engineer approves leaving the auxiliary gate valve and box in place, remove to at least 3 feet below the pavement surface under the road or at least 12 inches below planned grade outside the road. Stockpile the removed material at a location approved by the Engineer . The municipality will maintain ownership of the hydrant and remove the assembly from the project site.
P.Relocating Fire Hydrants. If the plans show relocating a hydrant, arrange for the municipality to shut down the existing main. Remove the hydrant and reinstall at the required location. Add extension sections as necessary to adjust the hydrant to the required elevation. Reconnect the hydrant to the water main by shutting down the main, t apping a new hydrant outlet, or using the existing outlet . Install ductile iron ( DI) class 54 piping as required.
Q.Abandoning Gate Wells . Abandon existing gate wells in accordance with section 203. Salvage the cover if requested by the municipality.
R.Gate Wells, Remove. Remove existing gate wells in accordance with section 203 and salvage existing gate valve. Stockpile the removed MDOT Standard Specifications for Construction Section 823 8-224 material at a location approved by the Engineer . The municipality will maintain ownership of the gate valve and remove it from the project site.
S.Miscellaneous Fittings. Install the following at the locations shown on the plans and in accordance with good construction practices:
1.Elbows ;
2.Tees ;
3.Corporation stops ;
4.Blow offs ;
5.Pipe adapters ;
6.Pipe couplings ;
7.Threaded rods ;
8.Casing chocks or skid units;
9.Retaining glands ; and
10.Other miscellaneous fittings.
T.Backfill . Protect trench backfill material against freezing, or thaw frozen material before using. Backfill in accordance with the MDOT Standard Plan R -83 series. Place backfill in horizontal layers no greater than 8 inches deep and to a height of 12 inches above the pipe. Place backfill equally on opposite sides of the water main at the same time. Compact , by tamping, each successive layer to at least 95% of the maximum unit weight . Completely fill and compact spaces beneath the pipe. During backfill operations around the pipe, avoid damaging pipe joints and coating and displacing the pipe from its original position.
U.Hydrostatic Testing . Perform hydrostatic testing of wat er mains in accordance with AWWA C600. Ensure that m unicipality personnel witness pressure testing. Give the municipality personnel at least 3 working day s notice before testing. Provide the personnel with temporary timber bracing, plugs, test pumps, temporary connections to the municipal water system, and other required apparatus . Provide the water for hydrostatic testing if not available from the municipality . Water must be from a measurable source in order to determine leakage. Before applying test press ure, expel air from the pipe. To expel air, make taps at the highest elevation points in the pipe. Plug these openings MDOT Standard Specifications for Construction Section 823 8-225 before the test with tight threaded brass plugs . Pressure test each section of water main in increments of no greater than 1, 000 feet. Do not perform testing against a closed valve that is in service. If leakage above the allowable limit occurs during hydrostatic testing, remove backfill to expose pipe and repair the joints and service taps . Repeat testing after repairs are complet e. Correct visible leaks regardless of the amount of leakage. Replace faulty pipes, fittings, gate valves, or other accessories disclosed by testing. Repeat the test until the pipes, fittings, gate valves, and other accessories meet the requirements.
V.Disinfection, Flushing , and Bacteriological Testing . Disinfect , flush and bacteriological test new and/or portions of existing water main in accordance with AWWA C651, EGLE regulations, and applicable local standards and regulations . The municipality may requir e a waiting period after flushing and before bacteriological sampling. Verify the quality of the water used for flushing and subsequent sampling. Use blow offs, fire hydrants, or other means as shown on the plans or approved by the Engineer to flush water mains . Provide hoses and other equipment and arrange a means of disposing of the water without damaging the work or adjacent property. Dispose of chlorinated water in accordance with applicable state and local requirements . If necessary, apply a reducing agent to the water to neutralize the chlorine and create a chlorine residual of no greater than 1 ppm. Collect samples from each branch of pipe in the presence of the Engineer and municipality personnel . The municipality will be responsible for the transpor tation of the samples to a State of Michigan approved laboratory for testing. Two consecutive bacteriologically safe tests at 24-hour intervals for each section of pipe are required . Acceptable tests are negative for bacteria and as otherwise defined by AW WA C651 and EGLE regulations . If a bacteriological test fails, repeat disinfection, flushing, and testing.
W.As-Built Plans . Prepare as -built plans as work progresses . Provide two complete sets of as -built plans to the Engineer within 30 days following completion of water main work . Include in the as -built plans the following information:
1.Pipe sizes ;
2.Pipe locations ; MDOT Standard Specifications for Construction Section 823 8-226 3. Fittings ;
4.Valve locations ;
5.Hydrant locations ;
6.Service tap locations ; and
7.The locations of underground obstructions that required r elocation of the water main installation.
X.Polyethylene Encasement . Install PE encasement on water mains and fittings in accordance with the manufacturer’s installation instructions and AWWA C105.
823.04 Measurement and Payment
Pay Item Pay Unit Water Main, DI, __ inch, Tr Det __ ............................................................. Foot Water Main, DI, __ inch (used for water main in a casing) ........................ Foot Gate Valve, __ inch ................................................................................... Each Live Tap, __ inch by __ inch ..................................................................... Each Water Main Line Stop, __ inch .................................................................. Each Gate Valve and Box, __ inch ..................................................................... Each Gate Well, __ inch dia ............................................................................... Each Water Main, __ inch, Cut and Plug ........................................................... Each Fire Hydrant .............................................................................................. Each Hydrant, Rem ........................................................................................... Each Hydrant, Relocate, Case __ ...................................................................... Each Gate Well, Abandon .................................................................................. Each Gate Well, Rem ........................................................................................ Each Gate Well Cover ...................................................................................... Each Water Serv ................................................................................................ Each Water Serv, Long ...................................................................................... Each Water Serv, Conflict .................................................................................. Each Water Shutoff, Adj, Temp, Case __ ........................................................... Each Gate Box, Adj, Temp, Case __ .................................................................. Each Water Shutoff, Reconst, Case __ ............................................................. Each Gate Box, Reconst, Case __ .................................................................... Each Water Shutoff, Adj, Case __ ...................................................................... Each Gate Box, Adj, Case __ ............................................................................ Each Polyethylene Encasement ......................................................................... Foot Water Main Conflict, __ inch. .................................................................... Each
A.Water Main, DI . The Engineer will measure Water Main, DI of the sizes and trench details required, along the centerline of the pipe, with no MDOT Standard Specifications for Construction Section 823 8-227 deductions for fittings . The unit price of Water Main, DI includes the cost of the following:
1.Excavation and backfill ;
2.Dewatering operations (trench and/or pipe);
3.Provide temporary water system to maintain service during construction;
4.Hydrostatic testing;
5.Disinfecting and flushing the water main and bacteriological testing;
6.All material, labor , and equipment necessary to remedy unsatisfactory hydrostatic and/or bacteriological test s, including removing and replacing any backfill;
7.Providing and installing fittings and gaskets, constructing skid units or casing chocks, installing the water main into a steel casing pipe and sealing the end of the steel casing, bracing or sheeting, blocking, providing temporary support of adjacent utilities within the limits of proposed water main construction and miscellaneous items for installing pipe and reconnect ing to the municipal water system;
8.Live taps and stops used at the Contractor’s option to expedite connecting to an existing water main;
9.Preparing and providing as -built plans. The Department may withhold payment until the Engineer accepts the as - built pl ans. The cost of dewatering trenches, pipe, or both associated with alterations to the municipal water system is included in the unit price for relevant items of work. The cost of excavating, disposing of excess material, and providing, placing, and compac ting the backfill is included in the unit price for related items of work. The cost of removing or abandoning existing water mains, gate valve boxes, and other appurtenances to provide clearance for the proposed water main or roadway is included in the uni t price for relevant items of work. The Department will pay separately for n on-structural flowable fill. MDOT Standard Specifications for Construction Section 823 8-228 B. Gate Valves, Gate Boxes, Live Taps, and Water Shutoffs
1.The unit prices of Gate Valve and Gate Valve and Box of the types and sizes required include the cost of providing and installing the valve and valve box, complete and ready for use.
2.The unit price for Live Tap of the size required includes the cost of providing and installing the valve, tapping sleeve, all necessary restraints, and valve box, complete and ready for use. This work includes the complete live tapping procedure.
3.The Engineer will measure and the Department will pay for Gate Box, Adj, Case __ and Water Shutoff, Adj, Case __ of the case required, as follows:
a.Case 1 refers to structures loc ated in hard surfaced travel areas , and the unit price includes saw cutting; removing and replacing existing pavement, curb, or curb and gutter ; and adjusting the water shutoff or gate box to final grade.
b.Case 2 refers to structures located outside existing pavement, curb. or curb and gutter , and the unit price includes restoring disturbed vegetated or sidewalk areas.
4.The Engineer will measure and the Department will pay for Gate Box, Reconst, Case __ and Water Shutoff, Reconst, Case __ of the case required, as follows:
a.The unit prices for Gate Box, Reconst, Case __ and Water Shutoff, Reconst, Case __ of the case required include the cost of provid ing and placing new sleeves, castings, and other materials above the existing valve.
b.Case 1 refers to structures located in hard surfaced travel areas , and in addition to costs shown in subsection 823.04.B.4.a, unit prices include saw cutting; removing and replacing existing pavement, curb, or curb and gutter ; and adjusting the water shutoff or gate box to final grade.
c.Case 2 refers to structures located outside existing pavement, curb, or curb and gutter , and in addition to costs shown in subsection 823.04.B.4.a , unit prices include restoring disturbed vegetated or sidewalk areas.
5.Gate Box, Adj, Temp, Case __ or Water Shutoff, Adj, Temp, Case __ will be measured and paid for if temporarily lowering the water shutoff or gate box . The unit prices for these Temp, Case __ pay items include the costs described for Case 1 pay items and the cost of temporary lowering work. MDOT Standard Specifications for Construction Section 823 8-229 The Department will pay for replacing damaged gate boxes or water shutoffs in accordance with subsection 823.03. J as the relevant gate box or water shutoff adjustment pay item . If the Engineer determines that gate boxes or water shutoffs were in poor condition or damaged despite Contractor precautions, the Department will pay for the work as the relevant gate box or water shutoff reconstruct pay item.
C.Gate Well
1.The unit price for Gate Well , of the diameter required, includes the cost of the concrete footing and up to 10 feet of structure depth. Gate Well Cover as detailed on the plans , including embossing required by the municipality, will be p aid for as Gate Well Cover .
2.The unit price for Gate Well, Abandon includes the cost of abandoning the structure and salvaging the valves if requested by the municipality.
3.The unit price for Gate Well, Rem includes the cost of removing the structure and salvaging valves for the municipality.
D.Water Service . Water Serv refers to services no greater than 30 feet long. Water Serv, Long refers to services greater than 30 feet long. Water Serv, Conflict refers to relocating only a portion of a water service. Services with a diameter larger than 2 inches will be measured and pai d for as water mains. The unit prices for Water Serv, Water Serv, Long and Water Serv, Conflict include the cost of the following:
1.Earth excavation;
2.Removing pavement;
3.Replacing pavement;
4.Jacking and boring;
5.Providing and installing type K copper tubing, service saddle, corporation stops, service stops, and service boxes;
6.Disinfecting;
7.Providing, placing, and compacting backfill ; and
8.Miscellaneous material, equipment, or operations. The Department will pay for additional service connections not shown on the plans but maintained, protected, and reconnected or disposed of by the Contractor as Water Serv, or Water Serv, Long . MDOT Standard Specifications for Construction Section 823 8-230 The pay item Water Serv, Conflict will apply only to portions of water services requiring relocation due to direct conflict with utiliti es, other items of work, or as otherwise approved by the Engineer . The Department will pay for all other relocations requiring replacement of corporation or service stops as Water Serv or Water Serv, Long .
E.Water Main, Cut and Plug . The unit price for Water Main, Cut and Plug includes the cost of cutting the existing water main, providing and placing the required plug, and thrust blocks.
F.Fire Hydrant . The unit price for Fire Hydrant includes the cost of providing and installing the hydrant, including the coarse gravel and concrete base, at the locations shown on the plans in a ready -for-use condition. The Department will pay separately for auxiliary valves or other items included in the contract as separate pay items. The unit price for Hydrant, Rem includes the cost of breaking down the auxiliary gate valve, gate box, hydrant assembly, backfilling , and plugging the opening in the existing main. The unit price for Hydrant, Relocate, Case __ of the case required includes the cost of vertically adjusting th e relocated hydrant to final grade and the following:
1.Case 1 includes the cost of removing the hydrant, extending the existing hydrant lead from the gate valve, reinstalling the hydrant in a ready -for-use condition, adjusting the existing gate box and hydr ant to final grade, and providing and installing sleeves, fittings, and thrust blocks or joint restraints.
2.Case 2 includes the cost of removing the existing hydrant, gate valve, and box ; reinstalling the hydrant and gate valve in a ready -for-use condition; adjusting the existing gate box and hydrant to final grade; and providing and installing the cutting- in-sleeve, pipe coupling, tee, elbow, thrust blocks , or joint restraints . If used at the Contractor's option, the cost of l ive taps is included in the uni t price for Hydrant, Relocate, Case 2. The Department will pay separately for Live Taps and additional pipe greater than 10 feet, where detailed on the plans.
G.Water Main Conflict . Water Main, Conflict, _ _ inch applies to those water mains where it is necessary to relocate a portion of the existing water main due to direct conflict with another utility or as approved by the Engineer . Water Main, Conflict, __ inch includes furnishing and installing pipe and misce llaneous fittings as needed. Excavating, backfilling , MDOT Standard Specifications for Construction Section 823 8-231 pavement cuts and repairs, jacking or boring, disinfection, supporting of existing utilities, and any other items or operations necessary to complete the work is not to be paid for separately but is to be included in Water Main, Conflict, _ _ inch. This pay item only applies at isolated locations where proposed water main is not otherwise being inst alled.
Source: Michigan Standard Specifications for Construction, 2020 Edition. Pages 780–792 of 1,146.