§ 11.1. General.

11.1.1 Scope.

1)

The contractor or developer shall furnish all equipment, labor, and materials (unless otherwise agreed upon in writing) necessary to construct reuse water mains and perform all work specified or indicated on the standard details. The work shall include all necessary concrete work, diking, pumping, bailing, draining, flushing, soil erosion and sedimentation control, and testing. These specifications cover reuse water mains and service connections complete. The reuse water mains shall be installed in the locations indicated on the standard details or as otherwise directed by the water and sewer system department (hereafter referred to in this article as "the department.").

2)

The contractor shall arrange his work so as to minimize interference with pedestrian and vehicular traffic, and to avoid interruption of service of any existing utilities. The contractor shall furnish and maintain suitable bridges, footways, or other means of access to or across intercepted streets, alleys, driveways and walkways, where necessary.

3)

Contractor shall perform all work in accordance with the latest revision of "Design Guidelines for Water Reclamation and Urban Water Reuse" of Georgia Department of Natural Resources, Environmental Protection Division.

4)

The contractor shall be responsible for removing all water from excavations and trenches whether from surface or ground sources.

5)

The contractor shall guarantee all material and workmanship for a period of 18 months from the date of final acceptance of the work. If during this period any material or workmanship, etc., proves defective, the contractor shall repair same at his own cost and expense and to the satisfaction of the department.

6)

In addition to the responsibility of the contractor for remedying observed defects in his work during the guarantee period, the contractor shall also reimburse the department for all expenses incurred in investigations to assure the department that the completed work is in accordance with these specifications.

11.1.2 Reuse water system flow demand.

1)

The developer shall provide hydraulic analysis of the reuse water system performed by a professional engineer registered in the State of Georgia.

2)

Design flow rates for each pipe shall be evaluated independently based on the number of residential units served as described in the following formula:

Q _D = (3.36 x N ^0.785 ) + 50

Where: Q _D = Reuse Water Flow in gallons per minute

N = Number of Equivalent Residential Units (ERU)

1 ERU = 300 Gallons per day

3)

Design flows shall be distributed equally at each residential unit. When flow rates are aggregated to nodes for analysis, flow shall be assigned to the most distant node from the source.

4)

Minimum reuse water delivery pressure at any point in the system shall be 45 psi when the system is operating at design flow rates based on a flow test conducted and approved by Paulding County.

5)

In any case, lines shall not be less than four inches in diameter:

11.1.3 Reuse water system water balance.

1)

The developer shall provide water balance calculations for the development performed by a professional engineer registered in the State of Georgia.

2)

The water balance evaluation is critical to ensure the same volume of wastewater being discharged from a particular development can be returned for irrigation purposes (i.e. balanced). The water balance evaluates the projected average daily flow (ADF) from the proposed development and compares this to the computed total reuse return application rate (Q _A ) considering each of the two application areas (residential lawns and irrigated open space):

3)

Calculations must illustrate the development will have adequate spray area to accommodate 100 percent of the sewage generated from the development as described in the following formula:

WB = (Q _A /ADF)

Where: WB = Water Balance Ratio

Q _A = Total Reuse Return Rate (gpd)

ADF = Average Daily Flow (gpd)

4)

A WB result of 1.0 or greater is required to meet the development's reuse demand.

5)

The average daily flow (ADF) for the development will be based on 300 gallons per day for each equivalent residential unit (ERU).

6)

The total reuse return rate for the development will be based on the residential and open space areas available to accept reuse water. Return rates for these two types of areas will be based on the formulas below.

Q _A = q _r + q _o

Where: Q _A = Total Reuse Return Rate (gpd)

q _r = Residential/Commercial Reuse Return Rate (gpd)

q _o = Open Space Reuse Return Rate (gpd)

q _r = 0.08(n x ai x i)

Where: q _r = Residential Reuse Return Rate (gpd)

n = Number of Residential Lots

a;sub    \sub; = Irrigable Area per Lot (Square Feet)

i = Reuse Application Rate (in/wk)

q _o = 3,336(Ai x i)

Where: q _o = Open Space Reuse Return Rate (gpd)

A;sub    \sub; = Irrigable Area per Lot (Acres)

i = Reuse Application Rate (in/wk)

7)

The reuse application rate (i) is generally accepted at 1.5 inches per week but can be adjusted at the discretion of the professional engineer based on the results of soil testing throughout the development. However, the reuse application rate will not exceed 1.8 inches per week.

8)

Only commercial areas associated with PRD type zoned developments will be included in the calculations for reuse.

11.1.4 Applicable specifications and standards. The latest editions of the following specifications, standards and publications setting the minimum requirements for quality, safety and performance of work and materials form a part of these regulations as though fully repeated herein:

ASTM	American Society of Testing Materials
ANSI	American National Standards Institute
AWWA	American Water Works Association
OSHA	Occupational Safety and Health Administration

 

11.1.5 Record standard details.

1)

The contractor shall be responsible for maintaining a set of the approved design standard details, which have been marked to reflect as-built conditions. These "record standard details" shall be kept at the site during working hours and shall be made available to the department's inspectors upon request.

2)

The record standard details shall show the as-built location of, but not be limited to, all lines, manholes, valves, hydrants, blow-off valves, monuments, etc.

3)

As-built locations shall be dimensioned to two permanent fixtures or objects and shall include coordinates tied to Georgia State Plane Coordinate system.