Two-Part Pump Test for Evaluating the Water-Supply Capabilities of Domestic Wells

An evaluation of the capability of a well drilled in rock to supply domestic needs can be based on predicted household water use patterns and characteristics of the well. Household water demand is estimated using a residency rate of two per bedroom and a usage rate of 100 gallons per capita daily. Water use is assumed to be split between equal morning and evening periods of peak demand. Rate of usage during peak periods is estimated at 3 gallons per minute per bathroom. Duration of the peak demand periods is estimated by dividing total usage during peak demand periods by the average rate of usage during peaks. Capability of the well to meet peak demand and total daily demand is evaluated through a two-part pump test. The first part, a peak demand test, is a drawdown test to determine whether or not the combined well storage and aquifer contribution to well flow can meet peak needs. The second part, a constant head test, is to determine whether or not flow from the aquifer is sufficient to meet total daily needs. If so it is assumed that the aquifer can meet long-term household needs. Measurements of drawdown during the pump test are used in determining the depth at which the pump should be placed in the well and the necessary depth if the well needs to be deepened to provide additional storage. The method does not take into account extreme droughts, interfering stresses on the aquifer from other pumping or decreasing efficiency of the well and pump due to aging.Hoffman, J.L. and Canace, R., 1986, Two-Part Pump Test for Evaluating the Water-Supply Capabilities of Domestic Wells: N.J. Geological Survey ground-water report series no. 1, Trenton, NJ, 12p.This document is for sale at the NJDEP's Maps and Publications Office NJDEP Maps and Publications Office Information - U.S. Postal Service purchases: DEP Map and Publication Sales Office P.O. Box 438 Trenton, NJ 08625-0438 - Over-the-counter and overnight delivery services purchases: DEP Maps and Publications Sales Office 428 East State Street (Carroll Building) Trenton, NJ 08608 Phone: 609-777-1038 Hours: 8:30 am-12 noon; 1 pm-4pm (Monday-Friday) - Credit card purchases: FAX credit card number, expiration date and signature to: 609-292-3285. Visa, Mastercard, Discover and American Express accepted. - Prepayment by check or credit card is required on all orders. - Make check payable to Treasurer, - State of New Jersey. Prices include shipping. - All sales are final.Purpose: A method for evaluating the suitability of a well for domestic supply