§ 7.5-94. Construction methods.

(1)

Licensing and safety. All contractors who work on sewer systems that will be owned by the city must be licensed in accordance with state law and local ordinance. Compliance with applicable safety regulations is the responsibility of each company engaged in the work; the city assumes no responsibility for the actions of others on the job site. It is the responsibility of those installing sanitary sewers, lift stations and related appurtenances to conform to OSHA regulations, 29 CFR Part 1926, Subpart P, Paragraphs 1926.650 through 1926.653. Publications from OSHA can be obtained by contacting OSHA Publications Distribution, Washington, D.C.

(2)

Construction permits. No construction shall be allowed until a construction permit has been issued by the city.

The contractor shall submit one (1) copy of the approved construction plans which have been stamped approved. The contractor shall furnish his name and address, telephone number. He shall also furnish the name, address and phone number of the person in charge of the project and any subcontractors and the name and telephone number of a responsible person who can be contacted in case of emergencies during nonworking hours.

The contractor shall furnish his construction schedule and shall notify the city one (1) business day prior to doing any work. Once the contractor begins work, he shall proceed in a workmanlike manner and shall complete the work in a reasonable time without undue off days and periods of inactivity which make it hard for the city to keep up with his activity.

(3)

Changes from approved plans. Any major changes from the approved plans will require that the engineer submit revised drawings along with a request explaining the reason for the change prior to construction of the change. Any deviation from city standards will be considered a major change as will any change that will affect capacity, longevity, operation or maintenance of the facility. Any deviation from approved materials will not be accepted without prior approval.

(4)

Trench excavation. Sewer lines shall normally be installed by open-cut trench excavation. Trenches shall be cut true to the lines and grades shown on the plans.

Pipe trenches shall not be excavated more than one hundred (100) feet in advance of pipe laying, and all work shall be performed to cause the least possible inconvenience to the public. Adequate temporary bridges or crossings shall be constructed and maintained where required to permit uninterrupted vehicular and pedestrian traffic.

All excavations shall be adequately guarded with barricades and lights in compliance with all OSHA and state department of transportation requirements so as to protect the public and workers from hazard.

Excavations adjacent to existing or proposed buildings and structures, or in paved streets or alleys shall be adequately protected by the use of trench boxes, sheeting, shoring and bracing to prevent cave-ins of the excavation, or the undermining or subsequent settlement of adjacent structures or pavements. Underpinning of adjacent structures shall be done when necessary to maintain structures in safe condition.

Streets, sidewalks, landscapes, and other public and private property disturbed in the course of the work shall be restored to as near as original condition as possible or better in a manner satisfactory to the city.

Trenches shall be kept free of water by pumping or well-pointing, as determined by the contractor. No structure shall be built or pipe shall be laid in water. Water shall not be allowed to flow over or rise upon any concrete, masonry or pipe until the same has been inspected and the concrete or joint material has thoroughly set. All water pumped, bailed, or otherwise removed from the trench or other excavation shall be conveyed in a proper manner to a suitable place of discharge. Such discharge shall not cause injury to public health, property, work completed, work in progress, or to any street surface, or cause any interference with the use of same by the public.

Construction occurring around active sewer systems shall be done in such a way so as to prevent the spillage of wastewater.

(5)

Rock excavation. Drilling and blasting operations shall be conducted with due regard for the safety of persons and property in the vicinity and in strict conformity with requirements of all ordinances, laws and regulations governing blasting and the use of explosives. Rock excavation near existing pipelines or other structures shall be conducted with the utmost care to avoid damage. Injury or damage to other structures and properties are the sole responsibility of the installation contractor and shall be promptly repaired by the contractor to the satisfaction of the city and property owner. Rock in trenches shall be excavated over the horizontal limits of excavation and to depths as follows:

Size of Pipeline (in inches)	Depth of Excavation Below Bottom of Sewer Pipe (in inches)
4 to 8	6
8 to 18	8
18 to 30	10

 

The undercut space shall then be brought up to grade by backfilling with size #57 crushed stone material or approved equal.

(6)

Installation of sewer pipe. Construction stake-out will be required prior to construction of sewer lines. As a minimum, the horizontal alignment will be staked at one hundred-foot intervals and each manhole will be located with a centerline stake and two (2) offset hubs. "Cuts" to invert elevations will be shown for each manhole entry and exit pipe.

Pipe and accessories shall at all times be handled with care to avoid damage. Whether moved by hand, skidways or hoists, material shall not be dropped or bumped. The interior of all pipe shall be kept free from dirt and foreign matter at all times. Each joint of pipe shall be unloaded opposite or near the place where it is to be laid in the trench.

All such material that is defective in manufacture or has been damaged in transit or after delivery shall be removed from the job site.

Sewer pipes shall be joined by "push-on" joints using elastomeric gaskets to affect the pressure seal. The ends of pipe to be joined and the gaskets shall be cleaned immediately before assembly, and the assembly shall be made as recommended by the pipe manufacturer. Lubricant used must be non-toxic and supplied or approved for use by the pipe manufacturer. Sewer pipes shall be laid in the uphill direction with the bells pointing upgrade. Any variation from this procedure shall require approval from the city.

When pipe laying is not in progress, the open ends of installed pipe shall be plugged with a watertight plug to prevent entrance of trench water into the line.

Bedding for pipe shall normally be as listed below (also see city standard details):

For PVC the minimum bedding shall be #57 or #89 crushed stone a minimum of six (6) inches below the bottom of the pipe to six (6) inches above the top of the pipe for the full width of the trench.

For concrete and ductile iron pipe the minimum bedding shall be #57 or #89 crushed stone a minimum of six (6) inches below bottom of pipe and initial backfill to the top of pipe for the full width of the trench.

In wet areas, the minimum bedding requirements will be increased as required to ensure a stable support under the pipe and on the sides of the pipe.

Backfill material up to twelve (12) inches above the top of the pipe shall be compacted dry, loose, soil unless PVC is used in which case the first six (6) inches above the top of pipe is required to be crushed stone. If such material is not available from the site then #57 stone shall be used to backfill up to twelve (12) inches above the top of the pipe. Backfilling the remainder of the trench may utilize soil and blasted rock (not over twelve (12) inches in any dimension) compacted sufficiently to avoid excessive settlement. Under no circumstances will tree parts, vegetation, building materials or any other type of debris be used for backfill.

All backfill beneath roads, sidewalks or other critical areas shall be compacted to ninety-five (95) percent Standard Proctor or as otherwise required by the DOT or other such agency having jurisdiction using mechanical tamping equipment. Moisture control of the material may be required to achieve this compaction and hauling in of select material may be required. Compaction testing and certification by an independent soil testing company will be required in these areas at the developer's expense.

(7)

Railroad crossings. All railroad crossing shall conform to the requirements of the American Railway Engineering Association Manual for Railway Engineering, Part 5. The contractor shall secure permission from the railroads to schedule the work so as not to interfere with the operation of the railroads. The contractor shall be held responsible for any delays or damages occurring to the railroads. The contractor will furnish the railroad with such additional insurance as may be required, cost of same to be borne by the contractor, together with the costs for flagmen, watchmen, temporary work of any nature, safety devices and any other items that may be imposed by the railroad.

(8)

Highway crossings. All construction work in the state highway right-of-way shall be approved by the state department of transportation. Developer shall be responsible for obtaining encroachment permits.

(9)

Stream crossings. The preferred method of crossing a river, stream, creek, impoundments, or wet weather ditch is with a minimum of six (6) inches of cover between the lowest point in the stream and the top of outside diameter of the pipe. Ductile iron pipe is required for all stream crossings and shall extend a minimum of ten (10) feet beyond the top of bank on each side. Concrete collars or encasement must be provided at all joints for ductile iron pipe with less than three (3) feet of cover.

The stream bed and sides at the crossing site shall be protected from erosion with the use of riprap, as defined and sized in the Manual For Erosion and Sediment Control In Georgia, Appendix C—Construction Materials, 1992 or most current or amended edition.

Aerial crossings will require detailed plans and will be allowed only when, in the city's opinion there is no reasonable alternative.

Erosion control measures shall be installed prior to installing pipe across any stream. All work should be performed when stream flows are at their lowest, and all work should be performed as quickly and safely as possible. As soon as conditions permit, the stream bed shall be cleared of all falsework, debris, and other obstructions placed therein or caused by the construction operations. Erosion control measures can include, but are not limited to, the following items:

(a)

Silt fencing, types A, B, and/or C.

(b)

Erosion control checkdams.

(c)

Channel diversion through temporary storm drain pipe.

(d)

Rock filter dams.

The construction and installation of these various structures are detailed in the Manual for Erosion and Sedimentation Control in Georgia or the state department of transportation standards and construction details, both of which are available for purchase by the contractor.

(10)

Casing for sewers. Where pipe is required to be installed under railroads, highways, streets or other facilities by jacking or boring methods, construction shall be done in a manner that will not interfere with the operation of the facility, and shall not weaken the roadbed or structure.

The diameter of the bore shall conform to the outside diameter and circumference of the casing pipe as closely as practicable. Any voids which develop during the installation operation shall be pressure grouted. Each segment of the casing pipe shall be welded (full circumference butt weld) to the adjoining segment. The completed casing shall have no sags or crowns which cause the grade for any segment to be less than the minimum slope for the size pipe being installed.

The carrier pipe shall be fitted with approved spacers to secure its position within the casing. At each end of the casing pipe the void between the carrier pipe and casing shall be sealed with brick and mortar.

(11)

Replacement of pavement. Contractor shall fully restore and replace all pavement, curbs, gutters, sidewalks and other surface structures removed or disturbed, to a condition that is equal to or better than the original condition in a manner satisfactory to the city (see standard details).

(12)

Location/protection of existing underground utilities. It is the responsibility of the contractor to locate all underground utilities and to protect same. Utility lines or services damaged by the contractor shall be repaired by the contractor at the contractor's own expense. The contractor has sole responsibility of complying with all provisions of the Utilities Protection Code.

(13)

Protection of water supply and other utilities. The city has an established cross-connection program (3/6/86) to prevent the entry of contaminants or pollutants into any area of the potable water supply through the control of cross connections. It is illegal to introduce any substance into or to have any cross connections with the potable water supply. There shall be no physical connection between a public or private potable water supply system and a sanitary sewer which would permit the passage of any sewage or polluted water into the potable water supply.

Whenever possible, sewers should be laid at least ten (10) feet horizontally from any existing or proposed water main. Should conditions prevent a separation of ten (10) feet, the lines shall be laid in separate trenches.

(14)

Sewer services. A sewer service shall be provided for every existing or proposed lot or building. All sewer services shall be a minimum of six (6) inches in diameter unless otherwise specified. All service lines shall be designed to maintain a minimum of two (2) feet/second sewer velocity. All services shall be shown on the construction and as-built drawings. A common service shall not be allowed for two (2) or more buildings. The service shall extend to five (5) feet inside the property line of the lot being served and normally be within ten (10) feet of the lower corner of the lot. All service laterals shall be a minimum of five (5) feet deep at the property line. Where five (5) feet of cover cannot be achieved, sewer services shall be constructed of ductile iron. A ninety-degree bend, constructed from two (2) forty-five-degree fittings shall be installed at the end of all sewer services with a vertical section of pipe to extend a minimum of four (4) feet above existing ground level (See standard details). Connections to the main exceeding eight (8) feet in depth may have the saddle or tee rotated to a bend inserted in the service to provide five-foot lateral depth at the property line.

The developer shall be responsible for serving all lots developed. On any lot where the service cannot be found, the developer shall be responsible for payment of the cost of installation of the service. Also, unless noted on the final plat, the service shall be low enough to serve the first floor elevation at the building line.

Install fourteen (14) gauge detector wire on all laterals.

The builder shall be responsible for the location of the service prior to the pouring of the foundation, driveway or other appurtenance. The city will not be responsible for any house built too low to be served nor for any service covered by construction.

No plumber or contractor will be allowed to connect to the sewerage system except to the end of the service provided for his connection. Also, any service provided will be utilized without the installation of additional services.

(15)

Clean up. Prior to requesting the "completion of sewer construction" inspection, the contractor shall remove and dispose of in an acceptable manner all shipping timbers, shipping bands, spacers, excess materials, broken material, crates, boxes and any other material brought to the job site.

Any work areas within public right-of-way or property outside of the development that were damaged by the sewer construction shall be repaired or replaced with the same kind of material as existed prior to the damage occurring. All easement areas shall be cleared of trees, stumps and other debris and left in a condition such that the easement can be maintained by bush-hog equipment.

All shoulders, ditches, culverts, and other areas impacted by the sewer construction shall be at the proper grades and smooth in appearance. All manhole covers shall be brought to grade.

A uniform stand of grass or mulch for erosion protection, as defined in the Manual for Erosion and Sediment Control in Georgia, is required over all construction easements and sanitary sewer easements prior to the city's acceptance of the sewer. Use a grass mixture consisting of at least fifty (50) percent fescue.

(Ord. No. 32-98, § 1, 8-27-98; Ord. No. 50-98, § 7, 1-7-99)