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the spring through fall period of 1993 and analyzed for phosphorus, nitrogen and total suspended solids. VBWD plans to collect stream samples annually. In recent years, the water quality of Lake DeMontreville has ranged from relatively good during the early summer period to relatively poor during the late summer period (see Figure 4-8). The Secchi disc transparency data were compared to criteria used to denote the effects of nutrients on the general water quality and/or trophic conditions of a water body (NALMS, 1988). Based on these criteria, Lake DeMontreville would be assigned a trophic status of mesotrophic during May through June, and would be assigned a trophic status of eutrophic during July through September. This means that the lake's water transparency is relatively good during the early summer period. However, algal blooms throughout the late summer period result in poor water clarity. During 1989 and 1990, algal blooms during the late summer period were more severe than algal blooms noted during 1988, 1991, 1992, and 1993 (see Figure 4-8). The water transparency of Lake DeMontreville was within the hypereutrophic category during a portion of the late summer period during 1989 and 1990. The water transparency remained within the eutrophic category during the late summer period of 1988, 1991, 1992, and 1993. The data indicate water quality problems due to late summer algal blooms occur on an annual basis, but the severity of the blooms varies somewhat from year to year, in response to variations in climate and weather. Historical total phosphorus, chlorophyll a, and Secchi disc transparency averages (see Figure 4-7) indicate the water quality of Lake DeMontreville has varied somewhat from year to year. Results of a trend analysis of Lake DeMontreville water quality data showed no significant changes in total phosphorus, chlorophyll . or transparency (Secchi disc) over the 1971 - 1990 period. A significant change in all three indicators is needed to indicate a significant change in water quality. The long term average summer total phosphorus concentration from the take's epilimnion is 0.044 mg/L indicating the lake, on average, is eutrophic and rich in nutrients during the summer. The 1993 data were compared to criteria used to denote a lake's nutrient "status" (NALMS, 1988). Based on this comparison, Lake DeMontreville would be assigned a trophic status of mesotrophic. This simply means that the lake has a moderate quantity of nutrients. The data suggest that Lake DeMontreville exhibited better water quality in 1993 than occurred in previous years. The long term average epilimnetic summer chlorophyll A concentration of 33.3 mg/m3 indicates the lake responds to its nutrient load by producing expected algal blooms. A trophic status classification of eutrophic would result from these chlorophyll data. During the period 1971 through 1993, the average summer water transparency has varied from mesotrophic to eutrophic. The summer average suggests water transparency varies from relatively good to poor. However, the average value fails to depict the annual change from relatively good water transparency during the early summer period to poor transparency .during the late summer period. Therefore, even during years when the summer average suggested the lake's water transparency was good, water quality problems were noted throughout the late summer period. Lake DeMontreville was treated regularly with an algicide (copper sulfate) during the 1970's, but was not treated during the period 1978 through 1990. During the period 1991 through the present, the lake has been treated with copper sulfate each summer to control its algal population. A professional was hired to complete the treatment, which was coordinated f 23\82\045\SEC4.RPT\KMH 20 DRAFT: June 23, 1994