A. General Requirements.
1. Centralized water systems shall be developed and maintained so as to meet the standards of the Pennsylvania Department of Environmental Resources under Chapter 109 - Waterworks of its rules and regulations and the Public Water Supply Manual - Bureau of Water Quality Management Publication No. 15., 2nd edition.
2. Where a centralized water system is contemplated in a new subdivision or land development, a feasible water supply and distribution system shall be proposed before preliminary approval of the subdivision or land development. Detailed plans and specifications for the water system shall be submitted to and be approved by the municipal engineer before final approval. A permit for the system must be granted by Pa. DER before final approval.
B. Water Supply.
1. Quantity
a. The water supply shall be drawn from an adequate and reliable source which can supply in combination with storage facilities the water demands of the proposed service area, at all times. The water source in combination with storage facilities shall be capable of meeting fire flow demands according to Section II-C of this appendix as well as average daily consumption except that in systems not required to provide fire flow the source in combination with storage facilities shall be capable of meeting the peak hour demand.
b. The water source shall be capable of supplying 110 gallons per day per person (GPCD) and/or 400 GPD per dwelling unit, for the design population of the development or the service area. Testing procedures to determine the reliable capacity of the water source are set forth in Section VI of this chapter.
c. Water service to commercial or industrial developments shall demonstrate adequacy to meet projected demand from the specific project.
2. Quality
Source shall conform to the water quality requirements of the Pa. DER as set forth in their Public Water Supply Manual Bureau of Water Quality Management Publication No. 15 -Section 2.2 Treatment of the water supply shall be done in accordance with requirements set forth in the Public Water Supply Manual, Parts 4 through 12.
C. Reliability Criteria
All Utilities shall have a standby pump or pumps adequate to insure that the system can operate normally with the largest pump out of service. In addition, the following storage and equipment requirements shall be met by centralized water supply systems according to the size of the system.
1. Small Utilities servicing less than fifty customers shall have sufficient storage facilities to supply demand for a 24 hour time period with the source cut off.
2. Utilities serving greater than fifty but less than one hundred customers shall maintain a minimum distribution storage capability of 100% of the maximum 24 hour demand.
3. Utilities serving greater than one hundred but less than two hundred customers shall maintain a minimum distribution storage capacity of 100% of the maximum 24 hour demand and an auxiliary power generation source.
4. Utilities servicing greater than two hundred customers shall provide elevated storage facilities of sufficient capacity to meet National Insurance Service Office recommendations for fire protection, shall provide fire hydrants, and shall meet design standards of the American Water Works Association.
The NISO minimum requirements for low or medium value residential and commercial areas are indicated in the table below:
Zone | Rated Capacity GPM | Time Duration (Hours) | Residual Pressure at Rated Capacity |
Residential | 500 | 2 | 20 PSI |
Commercial | 1000 | 2 | 20 PSI |
D. Distribution Systems
1. Acceptable Pipe Materials
Pipe selected for distribution systems shall have been manufactured in conformance with the latest standard specifications issued by the American Water Works Association. The following are generally acceptable materials for water main use:
a. Cast iron pipe (cement lined)
b. Ductile iron pipe (cement lined)
c. Steel pipe (for large size mains)
d. Reinforced concrete pipe (for large size mains)
2. Main Sizes
Water distribution mains shall be a minimum of 6 inches inside diameter laid out in a well-gridded system. Whenever fire protection capability is provided, main sizes shall be adequate so the system can meet the water quantity and pressure standards in Sections II-A and II-C of this appendix. Supply mains not adequate for fire-fighting shall not be connected to fire hydrants and can only be considered for use as special water service lines.
3. Water Pressure
A minimum static pressure during peak hourly flow of 50 pounds per square inch is desirable, but the minimum of 20 pounds per square inch should exist at any point in the system during periods of fire flow.
4. Customer Connections
a. All service connections from the main to a single dwelling unit shall be a minimum of 1 inch ID. The diameter of service connections to multiple units shall meet the approval of the municipal engineer.
b. Customer service connections shall be one of the approved materials for mains. Heavy wall copper may be used for service connections where soils are not permitted or subject to acidic ground drainage waters.
c. A curb stop shall be furnished for each customer service connection.
d. Cross connections - A cross connection is any physical connection, direct or indirect, which provided a potential opportunity for nonpotable water to enter a conduit, pipe or receptacle containing potable water. Such cross connections are prohibited.
5. Leakage Test
a. No installation shall be approved until the leakage is less than the number of gallons per hour as determined in the formula:
L= ND √ P
3700
3700
where:
L = allowable leakage in gallons per hour.
N = number of joints in the length of pipe tested.
D = nominal diameter of the pipe in inches.
P = the average test pressure during test.
b. Leakage tests are conducted by measuring the amount of water which enters the test section under normal working pressures for a period of at least 2 hours.
E. Water Storage and Pumping Stations
1. Storage for finished water should be provided as an integral part of each water supply system. Standards set forth in Part 14 of the Public Water Supply Manual - Tanks, Standpipes, and Pressure Tanks, shall be used in designing water storage systems. Equipment selected shall have been manufactured in conformance with the latest standards and specifications issued by the American Water Works Association.
2. Pumping stations within centralized water systems shall comply with standards and specifications set forth in Part 13 of the Pa. DER Public Water Supply Manual
F. Well Construction and Location
1. Well construction shall take place according to the standards set forth in Part 3 of the Pa. DER Public Water Supply Manual.
2. The centralized water system well course shall be centrally located within an open space water protection zone a minimum of 1 acre in size. No structures other than water system pumping stations, standpipes, etc. shall be located within the protected zone. No on-lot sewage disposal system shall be constructed within 200 feet of the water source well.
G. Well Capacity Testing Procedures
1. A dynamic recovery rate and draw-down test shall be conducted to determine the capacity and safe daily yield of the well source. The test procedures shall be conducted as follows:
a. A water pump, capable of variable output, having sufficient capacity to exceed the Dynamic Recovery Rate of the water source shall be employed for said test. It is recommended that the capacity of the source pump be such that draw-down to within 20 feet of the source pump be achieved in a maximum of 3 hours.
b. A suitable calibrated water meter capable of measuring the water output shall be connected to the water source pump outlet.
c. The exact location of the water source pump with respect to the bottom of the well shall be recorded and maintained constant for the duration of the test.
d. The water source pump shall be operated at maximum capacity and output for the first 6 hours of the test or until the water level in the source well reached a point 20 feet above the water source pump. The elapsed time and rate of pumping shall be recorded at 60-minute intervals on the log data sheet form supplied.
e. Draw-down of the source well in feet shall be recorded at 60-minute intervals as well as the water draw-down of any required peripheral test hole wells* on the log data form.
f. Reduce the maximum rate of pumping by 10 gallons per minute (GPM) and continue pumping for the next 2 hours of test or until the water level reached a point 20 feet above the water source pump. The elapsed time, rate of pumping and draw-down of the source well and, where required, the peripheral test hole wells* shall be recorded on the log data forms at 60 minute intervals.
g. Continue the above procedure using the 2 hour time periods or the criteria of water level above the source pump until the conditions are such that the Dynamic Recovery Rate of the water source equals the pumping rate (dynamic equilibrium). The Township Engineer may increase the increment of GPM reduction where on site review of the data warrants such action. Note, as the Dynamic Recovery Rate is approached, the increment of GPM reduction will need to be reduced from 10 GPM to 8 GPM to 5 GPM — to n GPM —> 0. At this point, no detectable change in draw-down will occur. If any change in draw-down is detected, either plus or minus, dynamic equilibrium has not been achieved.
h. When said Dynamic Recovery Rate is reached, recore elapsed time, pumping rate and draw-down on log data sheet and continue pumping at this rate for the remainder of the 72 hour test time or a minimum of 24 hours, whichever is the greater time. Elapsed time, pumping rate and draw-down of the source well, and where required, the peripheral test wells*, shall be recorded hourly.
i. Measurements of static water level recovery shall be made on the source well and peripheral test hole wells*, where required. Measurements shall be taken hourly and the data recorded for a minimum time period of 24 hours upon cessation of the dynamic recovery rate test.
j. Calculations of Specific Capacity and safe daily yield of the source well shall be submitted to the Municipal Engineer and the PDER by the registered professional engineer employed by the Utility or developer for review and analysis.
*Peripheral test hole wells may be required in order to determine the area of influence of the source well and the capacity of the source well aquifer. Peripheral test hole wells will generally be required in geological areas with slate and shale formations. The test hole wells shall be situated according to figure 1 and have a minimum diameter of 6 inches.
H. Improvements Requirements
1. Where a centralized water system is to be installed within a proposed subdivision or land development, the improvement procedures and requirements set forth within the township subdivision chapter shall be followed. Improvements agreements, guarantees, inspections, and guarantee releases shall include consideration of the centralized water company in carrying out the procedures and requirements of the township subdivision- land development chapter.
2. Final specifications for the design and installation of the centralized water system shall be included as part of the improvements agreement between the developer and the Township Council. Final approval of the subdivision or land development plan shall not take place until such specifications are finalized within the improvements agreement and until the necessary improvements and maintenance guarantees are posted. Engineering review of the specifications for the water system by an engineer independent of the design engineer shall take place before signing of the improvements agreement and before approval of the final development plan.
FIG. I
