New York Codes, Rules and Regulations › Title 10 - DEPARTMENT OF HEALTH › Chapter - APPENDICES › Appendix 5-D › Section 5-D.4 - Well Yield and Water Flow

Current through Register Vol. 46, No. 28, July 10, 2024
Before being put into use, new and redeveloped public water
				  supply wells shall be tested for yield as specified in this section. Where
				  adequate hydrogeologic information and uniform conditions exist, or when an
				  experienced hydrogeologist or licensed professional engineer directs and
				  certifies the test, yield testing requirements may be modified by the local
				  health department having jurisdiction. Additional yield test requirements may
				  need to be met for other agencies having jurisdiction.
(a) Pumping yield tests shall be done for the
				minimum duration of time specified in Table 2. For wells completed in
				unconsolidated deposits, constant flow rate testing may be used. For wells
				completed in rock, a minimum of six hours of stabilized drawdown should be
				observed either at the end of the test or as a second test except as allowed
				under subdivision (d) of this section or except where the Department or local
				health department allows constant rate testing.
(b) Where water wells use ground water
				sources potentially influenced by surface water as indicated in Table 2, water
				quality shall be tested and/or monitored during the pumping yield test in
				accordance with Department guidance for the determination of ground waters
				under the direct influence of surface water.
(c) Periodic water level observations shall
				be made and recorded during initial drawdown, stabilized drawdown, and recovery
				periods. The recorded data shall be provided in tabular form to the local
				agency(ies) having jurisdiction. During the period of stabilized drawdown the
				stabilized water level shall not fluctuate more than plus or minus 0.5 foot
				(i.e., within a vertical tolerance of one foot) for each 100 feet of water in
				the well (i.e., initial water level to bottom of well) over the duration of
				constant flow rate of pumping. The water level at the endpoint of the
				stabilized drawdown period shall not be lower than the water level at the
				beginning point of that period. Water level measurement may be determined by
				steel tape, calibrated pressure gauge attached to an air line terminating at
				least five feet above the pump intake, electric sounder, or pressure
				transducer.
(d) If a stabilized
				pumping level is not achieved during the required test period or if the well
				does not recover to 90% of the initial water level within 24 hours after
				cessation of pumping, a thorough evaluation of the expected sustained
				performance of the well during seasonal or multi-year dry periods shall be
				prepared. This evaluation may involve additional hydrogeologic investigation.
				Such evaluation may be used in lieu of satisfying the objectives of subdivision
				(c) of this section only at the discretion of the reviewing agency(ies) having
				jurisdiction.
(e) The test shall be
				conducted at a pumping rate at least equal to the design pumping rate based on
				system demand.
(f) Water discharged
				during a yield test shall be discharged in a manner that avoids short
				circuiting of the pumped water back into the aquifer.
(g) For wells that have been subjected to
				hydrofracturing, the yield test shall not commence until redevelopment has been
				completed and, as a minimum, until the volume of water pumped/discharged into
				the aquifer has been removed from the well. After pumping, the hydrofractured
				well shall receive a water well yield test as outlined in this
				section.