Page 230
December 2009
Water System Design Manual
WAC 246-290-130(c)(iii) states that one acceptable approach for demonstrating source
reliability is to conduct a pumping test at the maximum design rate and duration. For DOH to
make a source reliability assessment, Section 7.3 and Appendix F specify the pumping test and
hydraulic parameter information that should be submitted to DOH in a project report.
Those information requests pertaining to the pumping test portion of the report are summarized
below:
·
Measurements of the static water level prior to pumping (in the test well and observation
wells, if any);
·
All water level data for both the pumping and recovery phases of the pumping test;
·
Graphical presentations of the data, as appropriate;
·
Transmissivity, saturated thickness, and hydraulic conductivity values/calculations for the
producing aquifer;
·
Storage coefficient and specific yield for the producing aquifer;
·
Delineation of the 6-month, 1-, 5-, and 10-year time-of-travel zones for each well;
·
Identification of any hydraulic connection with surface water; and
·
Conveyance of pumped water.
This document is divided into three main sections.
1.
Section 2.0 discusses the rationale of DOH basic pumping test procedures, and the
general approach for a water system to use when determining a pumping test protocol for
obtaining DOH new source approval. This is followed by a discussion of special aquifer
settings DOH has identified as having greater potential for concern regarding water
quality and the ability of the aquifer to provide a reliable source of water. Section 3.0 also
describes the basic pumping test requirements, provides the rationale behind their
selection, and presents a flow chart for a water system to follow for selecting a pumping
test.
2.
Section 4.0 discusses what to do if the test is improperly conducted or goes wrong, and at
what point the test would probably not produce adequate data for DOH to conduct a
source reliability evaluation.
3.
Section 5.0 discusses pumping test components and defines terms used throughout this
document.
The stand-alone pumping test procedures for each of the basic pumping tests are provided at the
end of this document. These procedures summarize the basic instructions for the step drawdown
and constant rate discharge-pumping test, including specific instructions for sources with
concern for saltwater intrusion.