GROUNDWATER IMPACTS FROM WASTEWATER LAND DISPOSAL
SYSTEMS IN WISCONSIN
Michael D. Witt, Environmental Engineer
David K. Sauer, Environmental Engineer
Wisconsin Department of Natural Resources
Madison, Wisconsin 53707
INTRODUCTION
The use of land disposal systems in Wisconsin has come about due largely to the agricultural-
based economy of the state. Wisconsin is a national leader in the production of a multitude of dairy
and vegetable products which are processed and distributed to large areas of the country. Table I
summarizes the production of some of these commodities in the state.
These commodities are processed in a variety of facilities in the state. From these facilities a large
volume of wastewater is generated which must be disposed of.
REGULATORY PROGRAM FOR LAND DISPOSAL SYSTEMS
Over the last 15-20 years, the generation of wastewaters at municipalities, dairies, canneries, meat
processors and other industries has resulted in the need to establish sound practices for the disposal
of these wastewaters in an environmentally acceptable manner. Prior to this time the problems were
not as pronounced due to a larger number of smaller facilities which minimized the potential for
problems in a given area. For example, in 1950, 1,279 cheese factories were operating, but this number
had dropped to 306 in 1983. During the same time, however, production of cheese went from approximately 0.56 billion lb to 1.73 billion lb. As factories became larger, the volume of wastewaters
also increased with associated problems of over-application of wastes, use of poor sites, and inadequate separation distances, resulting in waste reaching surface and groundwaters, causing complaints
from the public and contamination of the water. The need to control these land disposal practices
was recognized in 1973 when the Wisconsin legislature included in the Wisconsin Pollutant Discharge
Elimination System legislation, the protection of groundwaters as well as surface waters. This provided that wastewater discharge permits be issued to facilities with land disposal systems. The program was integrated with the nationally developed permit program as included in the 1972 Federal
Water Pollution Control Act Amendments and as delegated to the state.
The Department of Natural Resources was established as the lead state agency for this regulatory
program. Under this program, a total of over 2100 facilities have been issued discharge permits, of
Table I. Dairy and Vegetable Production in Wisconsin [1,2,3]
Product
Production
Rank Among States
% of U.S.
Milk
23.8 billion lb
1
17.0
Butter
304.7 million lb
1
23.4
Cheese
1.7 billion lb
1
35.9
Sweet Corn
562,120 tons
2
20.5
Peas
147,920 tons
1
28.4
Green & Wax Beans
190,280 tons
1
29.5
Beets for canning
60,120 tons
1
38.6
Cabbage for sauerkraut
91,700 tons
1
37.3
Cranberries
1.13 million bbl
2
38.2
183