Em4885 irrigation management practices to protect ground water

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CHAPTER 4
Note that buffering strips may also be used at the head of a field to reduce erosion from
large inflows. Some farmers will use a narrow strip at the top of a furrow to reduce erosion
from gated pipe streams.
SCS National Practice 393 addresses design of vegetative filter strips.
IP 5.02.03 - Gather and Reuse Surface Runoff (see IP 2.02.11)
OVERALL MANAGEMENT OBJECTIVE 6.00
PREVENT DIRECT AQUIFER CONTAMINATION VIA WELLS
Explanation and Purpose
Water wells are a direct link from the surface to ground water. Aquifer contamination can occur
because of movement of nutrients or chemicals from the surface down through the well. Another type
of contamination occurs when a well pierces two or more distinct aquifers. If one of the aquifers is
contaminated and the well is not properly constructed, water from the contaminated aquifer could
migrate to the clean aquifer.
Contamination can also occur through improperly abandoned wells. Abandoned wells must be
properly filled and capped so that there is no path from the surface to the aquifer.
Much of well construction and abandonment is covered by state law. Of particular interest is
Engrossed Substitute House Bill 1806 which amended many sections of the existing law and added
new sections. An important element of the new law is that all constructors of wells, whether licensed
or not, are to construct wells according to the Department of Ecology’s well standards. Well drilling
regulations are contained in RCW 18.104. Minimum standards for construction and maintenance of
wells are contained in WAC 173-160.
Of particular importance to prevent ground water contamination through wells is proper
abandonment procedures. Practice 6.00.04 addresses abandonment.
SCS National Practice 642 addresses design and construction of wells as does American Society
of Agricultural Engineers engineering practice EP400.1.