TABLE OF CONTENTS Pages Symposium 1 - the National Sea ...

depth decreases.
Improvements in transparencies during the recreational season, resulting from reductions in
phosphorus loads over the 1990-1996 period are not detectable in the presence of climatological
and other random variations.
Nevertheless, Walker (1998) concludes that over the 1975-1996 time frame increases in
transparencies are generally correlated with decreases in hatchery phosphorus loads. However,
clear evidence for this is lacking.
Final Outcome
Finally, after 14 years a consent agreement was filed with the Court in March 2000. It addresses
the amount of water and phosphorus the hatchery can discharge, the number of salmon that can
pass the lower weir, the water quality monitoring required for the watershed and the hiring of an
implementation coordinator to oversee implementation and compliance with the agreement.
The hatchery discharge of phosphorus will be phased down over the next six years to 175
pounds per year with no more than 55 pounds for any three-month period.
No more than 20 million gallons per day can be discharged (13,889 gpm).
Also, the phosphorus concentration of Platte Lake must not exceed 8 )g/L 95% of the time.
All inflows and discharge points will be measured twice per week for total phosphorus,
temperature, suspended solids and flows, and current watershed monitoring will continue until
compliance with the final 175-pound phosphorus standard has been demonstrated for five
continuous years.
The phased approach is needed to allow the facility to be renovated, a key component of the
program. Up to 7.5 million dollars have been approved for the renovation aimed at designing
state-of-the-art effluent controls. The parties feel that this agreement represents a model of how
government can successfully interact with concerned citizens to protect natural resources.
References
Grant, J., 1979. Water quality and phosphorus loading analysis of Platte Lake, 1970-1978.
Water Quality Division, Michigan Department of Natural Resources, Lansing.
Hirsch, R.M., J.R. Slack, and R.A. Smith, 1982. Techniques of trend analysis for monthly water
quality data. Water Resources, Vol 18, no. 1. pp 107-121.
King, D.L., 1999. Memorandum, re. Platte Lake, to T.R. Batterson, Michigan State University,
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