Em4885 irrigation management practices to protect ground water

5
CHAPTER 2
Nonpoint source pollution is usually the result of land-use activities. This includes dairies,
irrigated and dryland agriculture, logging, rangeland management, and food processing (disposal
of wastes). However, there are other significant sources of nonpoint pollution. These include:
1. Urban and suburban use of pesticides, herbicides, and nutrients.
2. Runoff from highways and other paved areas.
3. Maintenance of highway and railroad rights-of-way.
4. Mosquito abatement activities.
5. Naturally occurring contamination (arsenic-bearing bedrock in Snohomish County is
an example of naturally occurring pollution).
Agricultural and other nonpoint sources are addressed in the federal Clean Water Act. In
Washington State, comprehensive management plans were developed in 1979 under Section 208
of the Clean Water Act to address surface water impacts from nonpoint sources. These sources
included dairy farms, irrigated and dryland agriculture, forest practices, and storm water runoff.
The Best Management Practice (BMP) concept was developed at this time. BMPs are defined
as schedules of activities, prohibitions of practices, maintenance procedures, or other management
practices to prevent or reduce the pollution of surface and ground water quality. BMPs were largely
envisioned to be implemented on a voluntary basis as government funding was not then available.
To date, voluntary implementation of BMPs has achieved very limited sustained success.
Section 319 of the Federal 1987 Clean Water Act amendments also required states to develop
comprehensive nonpoint source pollution management plans. Funds to implement Section 319 were
also authorized. The Manual, which describes practices that can help protect surface and ground
water quality, was funded under Section 319.
At the state level, the Washington Water Pollution Control Act (Chapter 90.48 RCW) established
state policies and requirements to protect both surface and ground water. Water quality standards for
surface and ground water were also established in formal agency rule or WAC (Washington Administrative
Code). WAC 173-200 addresses ground water quality and WAC 173-201A addresses surface
water quality. These standards establish maximum contaminant levels (MCL) that protect the various
beneficial uses.
State and Federal agencies recognize the contribution to pollution not only from agriculture, but
from all of the activities identified previously. For example, Chapter 70.95 of the Revised Code of
Washington (RCW) requires cities and counties throughout the state to develop local solid waste
management plans. Chapter 70.105 requires development of hazardous waste management plans.
A priority for both laws is reduction in the amount of waste that is discarded, including garden
pesticides and fertilizers. Another example of response is the BMPs manual for reduction of
nonpoint source pollution by forestry practices that is incorporated in the Forest Practices Rules
and Regulations (WAC 173-202).