Stauffer has installed, as a result of a 1976 Board of 

 Health and Environmental Sciences order, abatement equipment 

 on the nodulizing kilns, a furnace taphole scrubber, a 

 phosphorus handling system, and the roaster. Prior to that 

 order, Stauffer had also installed turbalaire scrubbers on 

 various transfer and handling facilities to control dust. 

 Some of the equipment, notably the furnace taphole scrubber, 

 has not lived up to expectations and the DHES-Air Quality 

 Bureau was forced to issue a departmental order on the 

 facility in February 1987. Stauffer is in the process of 

 bringing the taphole scrubber stack into compliance with 

 state visual emission standards. 



Until 1972, untreated process wastewater from the plant 

 was discharged directly into Silver Bow Creek. At that time, 

 Stauffer began construction of a closed system to recycle 

 process wastewater. The system was completed in 1975, and 

 further improvements made in 1979 and 1982 have reduced the 

 risk of contaminant discharge to Silver Bow Creek (CH2M Hill 

 1983) . 



IRRIGATED AGRICULTURE 



Introduction 



Irrigated agriculture in seven of the Clark Fork 

 subbasins consists of approximately 400,000 acres of cropland 

 supplied with water from projects operated or managed by 

 private water users and state and federal government agencies 

 (DNRC 1986) . According to figures published by the DNRC in 

 1986, these projects withdraw approximately 1,764,000 AF of 

 ground water and surface water, which amounts to about 4 . 4 AF 

 withdrawn for each irrigated acre. Table 2-4 gives figures 

 for irrigated acreage served by ground water and surface 

 water in seven of the Clark Fork subbasins. 



The Agricultural Statistics Service of the Montana 

 Department of Agriculture (MDA) has compiled crop statistics 

 by county for irrigated agriculture (MDA 1987) . Using the 

 MDA's 1986 figures for Clark Fork Basin counties, the 

 percentages of irrigated acreage for eight major crops were 

 calculated. These percentages were applied to the total 

 irrigated acreage figure given in Table 2-4 to estimate the 

 irrigated acreage, by crop, for the Clark Fork Basin (Table 

 2-5) . 



The estimates in Table 2-5 indicate that more than 75 

 percent of the irrigated land in the Clark Fork produces hay 

 crops, with alfalfa alone accounting for nearly one half. 

 Just over 20 percent of irrigated lands are used for small 

 grain production. Potato and corn silage production together 

 account for 2 percent. 



2-7 



