Lake Description
Peppermill Lake is located in southeast Adams County, approximately 4 miles west of Oxford, Wisconsin. The lake has a surface area of 100 acres, with a maximum depth of 14 feet and a mean depth of 7 feet. Peppermill Lake is the headwaters for Peppermill Creek, a tributary of Neenah Creek. Peppermill Creek has a diverse warm water fishery. The macrophyte indices and instream habitat assessments are satisfactory (The Sate of the Upper Fox River Basin, 2001). The water source for the lake is surface runoff and groundwater springs. The University of Wisconsin-Stevens Point Environmental Task Force Program evaluated the groundwater entering the lake in 2001. Groundwater generally flows northwest into the lake and flows east out of the lake. The University of Wisconsin-Stevens Point Environmental Task Force Program also determined that stratification occurs in the deep holes during the winter and summer months, while mixing occurs in the spring and the fall. The Peppermill Dam, built in 1967, impounds water to form the lake. Adams County owns, operates, maintains and repairs the dam. A public boat launch located at the east end of Peppermill Lake. Adams County Parks and Recreation Department manages the boat launch and immediate area.

Climate
The climate in the Peppermill Lake area is classified in the continental climate type. The summers have warm but not excessively hot, days and cool nights. Winters are long, cold, and snowy. Mean annual precipitation is almost 30 inches. In an average winter, snow cover on the ground and ice cover on the lakes lasts from December to April. The growing season generally extends from late May to early September, for an average frost-free growing season of 135 days. Prevailing winds come out of the northwest from late fall through spring and from the South during the remainder of the year. The wind speed generally ranges from 4 to 15 miles per hour. (Adams County Land and Water Resource Management Plan)

Demographics
Peppermill Lake is in the Town of Jackson, Adams County, Wisconsin. The 1995 town population was 953. In 2000, the population of 926 was 55.4% between 19-65 years old and 22.2% over 65. There were 951 total housing units, with 41.7% of those units being occupied year round and 58.3% seasonally/recreationally occupied. The median household income in 1999 was $39,338 with 25.5% in the $35,000-$49,999 range, 22.9% in the $50,000-$74,999 range, and 20.2% in the $15,000-$24,999 range. The industry is varied in the Township with manufacturing 20.1%; recreation 13%, education/social services 11.3%; and retail trade 11.3% being the top four. (U.S. Census Bureau, Census 2000)

The Peppermill Lake Association/District conducted landowner surveys in 2001 and 2004 to determine lake use, perceptions, and practices that may affect the lake water quality. Fishing, boating, peace/solitude were the top recreational activities for lake users in 2001, while in 2004, fishing, boating, peace/solitude, and scenic enjoyment were the top recreational activities. The 2001 survey attempted to gather information on septic systems, but response was incomplete. The 2004 survey results stated on average, survey respondents’ septic systems were inspected every 1-2 years. The 2004 survey results stated 70% of the respondents felt the lake level has not changed significantly, and 65% said there should be no adjustments to the lake level. Other results of the surveys:

Lake Water Quality
The relatively shallow nature of Peppermill Lake and its impoundment status make this regionally popular water resource sensitive to nutrient inputs (Assessment of Lake and Groundwater Chemistry, Shallow Groundwater Flow, and the Aquatic Macrophyte Community, Peppermill Lake, 2002). Wisconsin Department of Natural Resources (WDNR) Self-Help data has been collected and analyzed according to DNR criteria. The lake water clarity is very good, and the lake water quality is good to very-good. The watershed to lake ratio is 9.5:1. Negative water quality impacts from the watershed are generally seen when the drainage area/lake size ratios exceeded 10:1.

The Adams Land and Water Conservation Department is presently testing the water quality from 2004 to 2006 and plans to monitor water quality in the future. The University of Wisconsin-Stevens Point Environmental Task Force Program evaluated the water quality and found:

1. Total phosphorus and total nitrogen levels are at manageable levels;
2. Modeling predicted 135-kg/year total phosphorus entering the lake (75% from ground
   water flowing through lake sediments, 10% from watershed, 7% from groundwater,
   5% from septic systems, and 3% from atmosphere);
3. Phosphorus is the limiting nutrient in Peppermill Lake;
4. water flow into the lake is estimated at 4 to 4.5 cfs;
5. The lake’s Trophic Status Index is mesotrophic to eutrophic;
6. Toxic metals will not be an immediate factor in water quality due to the high pH and
   buffering capacity;
7. The measured amount of chloride indicates a minimal impact from septic systems,
   animal waste, fertilizers, regional watershed activities, and road salting chemicals;

Based on tissue phosphorus concentrations of aquatic plants in other Adams County lakes, the DNR estimates removing 40 to 90 tons of aquatic plants per year would likely counteract an estimated 135 kg/year phosphorus entering the lake via the watershed. The tonnage of aquatic plants mechanically harvested in 2003 was in this range.

The 2001 and 2004, surveys of the Peppermill Lake Community found weeds were perceived as the major water quality problem, followed by algae and water clarity. The 2004 survey results showed those who see water quality declining felt it is due to weeds (56%), development (23%), septic systems (20%), and herbicides (16%). Other results:

Aquatic Plant Community
In 1998, Eurasian watermilfoil was identified as a potential large-scale problem, but the native plant community was effectively competing with the Eurasian watermilfoil. Chemical control was begun on 1999. Aquatic Engineering Inc. conducted an aquatic plant survey in 2003 and identified a possible hybridized form of watermilfoils as the greatest threat to aquatic plant management. Eurasian watermilfoil and hybrid watermilfoils utilize nutrients in the lake for growth, and fragments of the plant may spread to new areas and become established. Eurasian watermilfoil and hybrid watermilfoils are a problem because they can prevent navigation, reduce lake aesthetics, impair fisheries and out-compete native plant communities (Peppermill Lake District Aquatic Plant Management Technical Report, 2003).

In 2001, the University of Wisconsin-Stevens Point Environmental Task Force Program completed a plant survey that found the aquatic plant community is above average quality according to the Aquatic Macrophyte Community Index. The plant survey also provided the following findings: the sediment is predominately silt; 97% of the littoral zone is vegetated (25-85% is ideal for fish habitat); many of the plants found are excellent fish habitat and are characteristic of good water clarity; there is good diverse submergent plant community, while the emergent plant community lacks diversity.

In 2003, Aquatic Engineering Inc. conducted 4 surveys, starting in June and ending in mid-October, to identify areas of Eurasian watermilfoil. The areas were treated with 2,4-D and totaled 5.4 acres. During the follow-up periods, it was determined that previous treatments controlled the Eurasian watermilfoil, but the 2,4-D had no control on the hybrid watermilfoil growth. Timing, water temperature, and slow plant metabolism may attribute to the poor treatment results on the possible hybrid watermilfoil. For details of the surveys and treatments, review “2003 Peppermill Lake District Aquatic Plant Management Technical Report.

In 2004, Aquatic Engineering Inc. developed and implemented a plan to reduce the frequency of Eurasian watermilfoil and hybrid watermilfoil by chemical means. The initial survey found Eurasian watermilfoil and hybrid watermilfoil. On June 17, 2004, granular 2,4-D was applied to small areas of Eurasian watermilfoil and hybrid watermilfoil infestations. On June 21, 2004 liquid 2,4-D was applied in areas of large infestations. The follow-up survey conducted July 19, 2004 showed the Eurasian watermilfoil and possible hybrid watermilfoil was controlled successfully.

The 2004 Peppermill Lake Survey stated 95% of the respondents supported general weed harvesting. 66% of the respondents wanted more plants to be harvested, 30% wanted the same amount as current, and 16% wanted fewer plants to be harvested.

In 2004, a survey of the Peppermill Lake Community found 66 % of the respondents rated the fishing average or better, while 20% rated it fair and 4% rated the fishing as poor. The survey showed approximately 56% of the respondents felt the quality of fishing had stayed the same, 45% felt it had declined and no one felt it had improved. Results of the survey showed those who felt the fishery was in decline felt it was due to over-fishing, weeds, and soil erosion.
In 2001, the University of Wisconsin-Stevens Point, Wisconsin Cooperative Fishery Research Unit evaluated the status of the fish community. Results of the survey found high numbers of small bluegill and low numbers of largemouth bass and northern pike. It was determined that high aquatic plant growth might be hindering predation and bluegill growth. Recommendations to improve black crappie, yellow perch, northern pike, and largemouth bass were: conduct a growth study of the bluegill population to determine if stunting or angler harvest is responsible for the current size structure of the population; mechanical harvest of aquatic vegetation in channels to create edge-effect; continued stocking of northern pike and largemouth bass; and fishing regulation changes.

WDNR conducted a fish survey in 1999 and compared the results with historic records of fish populations. It was determined that Northern pike and Largemouth bass populations have fluctuated over time due to natural causes, winterkills, stocking and more restrictive size and bag limits. The 1999 survey showed the following: Northern pike and Largemouth bass numbers were high; Northern pike size structure was good with a mean length of 20.6 inches; Largemouth bass size structure was slightly down with a mean length of 10.6 inches; Bluegill numbers have increased and their size structure has decreased with a mean length of 3.9 inches. WDNR concluded predatory control of bluegill was not occurring in Peppermill Lake due to the high density of aquatic vegetation in the lake. WDNR recommended mechanical harvesting of aquatic plants to create areas of open water to improve fish predation, navigation and fishing opportunities.

Between 1995-2004, volunteer lake owner groups installed the following fish habitat improvement projects: deposit of pea gravel at 9 near shore sites to improve bass spawning; construction and placement of fish cribs in 3 to 5 feet of water at 9 sites to provide cover; trees dropped into water at 10 strategic points on the shoreline to provide fish habitat; and fish stocked periodically.

In the 1970’s and early 1980’s, there were four severe winterkills of fish due to low dissolved oxygen levels from the decomposition of vegetation and organic material (Ironside, WDNR Fisheries Biologist, 1999). Two aeration systems were installed in 1992 to improve the low oxygen conditions.

Watershed
Total lake surface watershed is approximately 952 acres. The land use in the surface watershed is woodlands 53.4%, residential 36.2%, water 6.9% and agriculture 3.5%. The upper watershed consists of moderate to steep sloping, well to somewhat poorly-drained, sands and loamy sands. The shoreline area (area within 1000 feet of lake) consists of slight to moderate-steep slopes, with well-to moderately drained, sands and loamy sands. Residential development occurs on most of the 92 riparian parcels in the shoreline area, and most parcels have native herbaceous plants. There are approximately 80 acres of zoned conservancy on the north side of the lake. (Assessment of Lake and Groundwater Chemistry, Shallow Groundwater Flow, and the Aquatic Macrophyte Community,Peppermill Lake, 2002). The shoreline area is not serviced by a public sanitary system and all dwellings have private septic systems.

The groundwater watershed is approximately 4,715 acres, with groundwater generally flowing northwest to southeast. There are no high capacity drinking wells in this watershed but there is high capacity wells used for irrigating cropland.

In 2001, the University of Wisconsin-Stevens Point Environmental Task Force Program lead efforts to determine the quality of surface water and groundwater entering the lake, the land uses in the watershed and the effects they were having on the lake’s water quality. The groundwater was found to have hard water with elevated alkalinity and conductivity. Several samples had high levels of nitrate and chloride that may indicate minor impacts from watershed activities, septic systems, and shoreline area activities.
Surveys in 2001 and 2004 of the Peppermill Lake Community found:

Peppermill Lake District
The Peppermill Lake District was formed in 2002. The district board consists of 5 lake area residents, a Town of Jackson representative, and an Adams County representative. The district is responsible for the management of the lake.

Regulations
Adams County has a Comprehensive Zoning Ordinance that regulates land use, a Shoreland Protection Ordinance that regulates activities in areas within 300 feet of a stream and 1,000 feet of a lake, a Sanitary Ordinance that regulates on-site sanitary systems a Floodplain Ordinance that regulates activities within the flood plains, a Land Division Ordinance regulates division of properties and a Building/Construction Ordinance that regulates building and construction activities. The Town of Jackson utilizes the Adams County Planning and Zoning and their ordinances to regulate activities. Peppermill Lake has had a no-wake ordinance.

A survey of the Peppermill Lake Community showed 100% of the respondents support the no-wake ordinance. The survey also indicated that over 40% of the respondents enjoyed the quiet peacefulness of the lake, with many complaining about noises from lakeshore activities. (Peppermill Lake Survey, 2004)