The State of Webber Pond Understanding the Factors Affecting Water Quality in the Webber Pond Watershed Colby Environmental Assessment Team Colby College Biology Dept. December 5, 2002 Vassalboro Town Office PART 1

Presentation Overview Introduction Water Quality Analysis Land Use Analysis - Intermission - GIS Analysis and Models Future Predictions Remediation Measures Recommendations

An Introduction to the Study of Webber Pond Erin Estey

Study Objectives Measure Water Quality of Webber Pond: Physical parameters DO, Temperature, Turbidity, Conductivity Chemical parameters Total phosphorus, Nitrates, Hardness, pH, Alkalinity Compare to historical data DEP water sampling since 1972 Members of CEAT performing water quality tests.

Study Objectives Calculate proportion of Webber Pond watershed covered by various land uses: -Road surveys -Residence counts -Buffer strip surveys -GIS land use map analysis aerial map aerial map Residential development in the watershed

Study Objectives Project the future condition of the Webber Pond watershed: - Create Models - Calculate Phosphorus Loading Model - Calculate population trends - Project future development - Recommend best remediation techniques Septic suitability model

Characteristics of Maine Lakes Important resources in Maine: Recreational, Economic values Due to glaciations, many Maine lakes are oriented in a northeast to southwest direction A Webber Pond Sunset

Lake Strata

Lake Turnover Webber Pond is dimictic –Summer thermocline –Fall turnover –Winter stratification –Spring turnover Turnover re-oxygenates the lake, recycles nutrients

Trophic Status of Lakes

Nutrients Webber Pond is eutrophic, which means that it is high in nutrients. High nutrient levels (especially nitrogen and phosphorus) lead to large phytoplankton communities. Increased productivity leads to increased sedimentation and aging of the lake. The process of sedimentation over time.

Defining a Watershed Total area contributing flow to a particular basin. Defined as the highest points of land that surround it.

Historical Perspective of the Webber Pond Watershed 1950’s ’s large chicken farms. Now small vegetable farms, orchard, golf course, lakeshore residences Maine DEP began secchi disk sampling. Current algal blooms are not as severe as those in 1960’s ’s.

Reconstructed in 1986, it’s used to regulate water levels. Benefits of stabilizing water levels: –Minimize shoreline erosion –Provide stable environment for flora/fauna –Allows for flushing of high-nutrient water 33 percent of the lake volume can be drawndown with dam The Webber Pond Dam

Geographical Perspective of the Webber Pond Watershed Part of the Lower Kennebec River watershed A heavily populated area Webber Pond covers 1,238 acres The Webber Pond watershed covers 5,292 acres Webber Pond receives water from Threemile Pond, Threecornered Pond, Mud Pond Lower Kennebec River watershed

Biological Perspective of the Webber Pond Watershed Submerged aquatic plants around periphery Nine species of native fish: American Eel, Fallfish, White Sucker, Brown Bullhead, Chain Pickerel, Banded Killfish, Red Breasted Sunfish, Pumpkinseed, Yellow Perch Largemouth Bass, Smallmouth Bass, White Perch were introduced but not actively stocked Smallmouth bass (Micropterus dolomieu)

Fish Stocking of Webber Pond Brown Trout and Brook Trout have to be replaced due Webber Pond water quality. Alewives are anadromous, movement blocked by dams In the short-term, Alewives may deteriorate water quality In long-term, Alewives may help water quality Brook Trout Salvelinus fontinalis Sea-run Alewife Alosa pseudoharengus

Introduced Plants 11 species pose a threat to Maine lakes Problematic because: –spread by fragments –grow rapidly –outcompete natives –hard to eradicate, control Webber Pond is at a high risk because: –soft, shallow bottom –public access via boat ramp Eurasian Watermilfoil (Myriophyllum spicatum)

Water Chemistry Serena Vayda

Sample Site Locations 3 characterization sites 7 spot sites 4 tributary sites

Water Quality Assessment Methodology Insert picture of boat Sampling Dates: 28-Jun Jul Aug Sep Sep-02

Water Quality Parameters Physical Measurements: Dissolved Oxygen (DO) Temperature Transparency Turbidity Color Conductivity Chemical Measurements: pH Hardness Alkalinity Total Phosphorus Nitrates

Dissolved Oxygen (DO) DO: Measurement of concentration of O 2 in water column Stratification leading to anoxia Phosphorus implications Impact on fisheries

Transparency Transparency less than 4 m indicates eutrophic conditions September mean is 1.24 m 2001 mean is 2.8 m=Eutrophic Measures water clarity as an indicator of trophic state

Selected Test Results: (physical characteristics) Turbidity: Optical property-measures scattering and absorption of light in water column Webber Pond mean = 5.89 NTU Natural waters <50 NTU Color: Contributes to depth that light can penetrate water Mean = 18.5 SPU Comparable to other lakes in region

Conductivity: ability of water to conduct electrical current Mean = 39.3 µMHOs/cm Maine avg is 20 to 40 µMHOs/cm Physical Characteristic:Chemical Characteristic: Alkalinity: Capacity to neutralize acid High alkalinity can buffer against pH changes Mean = 37 ppm-good buffer

Selected Test Results: (chemical tests) pH: Measure of acid balance of a solution Maine lakes range between pH 6.1 and pH 6.8 Healthy lakes range between pH Webber Pond mean = 7.4 Hardness: Measure of total concentration of calcium and magnesium ions Mean = 2.91 ppm Soft lake Good for fish, vulnerable to algae blooms and phosphorus loading

Nutrient Levels Paul Mathewson

Nutrient Loading Plants need a variety of essential nutrients for growth Phosphorus and nitrogen limiting in aquatic ecosystems Cultural Eutrophication

Phosphorus Found in all soil types Common in fertilizers Septic systems / Animal waste Critical Limit = 12 ppb to 15 ppb Algal Bloom on a Florida Lake

Historical Phosphorus Mean Concentration = 28.2 ppb

Summer Phosphorus Data Mean Surface Concentration = 19.4 ppb Mean Mid-depth Concentration = 19.9 ppb Mean Bottom Concentration = 79.4 ppb Mean Epicore Concentration = 21.0 ppb

Fall Phosphorus Data Mean Surface Concentration = 35.7 ppb Mean Mid-depth Concentration = 34.6 ppb Mean Bottom Concentration = ppb Mean Epicore Concentration = 36.7 ppb

Spot Site Phosphorus Average Concentration = 30.6 ppb

Sediment Release Phosphorus accumulation in hypolimnion Oxygenated water: ferric phosphate Anoxic conditions: phosphorus release

Epicore and Bottom Phosphorus Concentrations in 2002

Historical Epicore and Bottom Phosphorus Concentrations Mean Epicore Concentration = 29.5 ppb Mean Bottom Concentration = ppb

Nitrates Common ingredient in commerical fertilizers Septic leaks / Animal waste Fixation by cyanobacteria Healthy levels under 1 ppm Mean concentration in Webber Pond = 0.07 ppm

Tributaries Knowledge of tributary water quality is essential to understanding the water quality of a lake Most tributaries seasonal and/or ephemeral Only four carrying water during fall testing Seaward Mills Brook

Tributary Phosphorus Mean Concentration = 81.5 ppb

Watershed Land Use Patterns Chris Makarewich

Land Use Assessment Land use types have varying effects on lake water quality Different surface covers influence surface runoff and erosion Assessment of land use patterns and historical trends essential to evaluate ecosystem health

Steps in Creating the Land Use Map 1.Obtain Digital Orthophoto Quads 2.Import into ArcView 3.2 (GIS computer program) 3.Determine land use categories 4.Digitize land use areas through polygons 5. Derive and summarize areas

What is a GIS? GIS = Geographic Information System Uses a common coordinate system Combine geographic data with theme values and attributes Creates layers of information for each theme

GIS Inputs

1997 Digitized Aerial Photograph Classification of land use types (Agriculture)

Completed 1997 Land Use Map Final Product

Land Use Categories Natural Uses Wetland Mature forest Transitional forest Reverting land Developmental Uses Agriculture Cleared Commercial / Municipal Golf Course Open Residential Land

Wetlands Transition from aquatic to terrestrial ecosystems Natural buffer against nutrients and sediments In 1997 covered 0.5% of watershed area

Closed, continuous canopy Best buffer from runoff and erosion In 1997 covered 15.7% of watershed area Mature Forest

At least 50% canopy cover Provide some erosion prevention as well as water and nutrient absorption In 1997 covered 49.7% of watershed Transitional Forests

Land succeeding from agriculture towards forest Results in a canopy cover of less than 50% In 1997 covered 7.7% of watershed Reverting Land

Land cleared for timber harvest Increases surface runoff and erosion In 1997 covered less than 1% of watershed No major logging companies Clearing of land carried out under zoning regulations Cleared Land

Agriculture Cropland Crop rows indicate planting Addition of pesticides and fertilizers In 1997, covered 9.1% of watershed Agricultural land with no planting rows Compaction leads to increased runoff Presence of animal waste Covered 4.7% of watershed Pasture

Nutrient Management Plans Qualifications for a nutrient management plan - more than 50 animal units -request federal funding -complaint registered Plans developed by a certifier trained by MDA Not examined unless a complaint is registered Currently 150 acres under nutrient management plans in the watershed Control amount of nutrients added to a field Maine Department of Agriculture (MDA)

Commercial and Municipal Land Golf Course All businesses and public facilities Impervious surfaces increase runoff Less than 1% of watershed area in 1997 Addition of fertilizers and pesticides In 1997, covered 3.4% of watershed Proximity to Webber Pond

Open Residential Land Land developed for the creation of homes Increased runoff adds to erosion Presence of septic systems In 1997, covered 7.1% of watershed

Historic Trends in Land Use

Summary of Land Use Changes Decreased agriculture Increased total forest area Increase in open residential land Careful to maintain mature forest tracts and wetlands in future

Land Use Analysis Madeleine Mineau

Shoreland Zoning Minimum residential lot size: 40,000 sq.ft Minimum residential shore frontage: 200 ft Maximum height of structures: 35 ft All structures are required to be set back a minimum of 100 horizontal feet from the normal high water mark.

Shoreland Zoning (continued) Campground: Camping areas shall contain a minimum of 5000 sq. ft of land for each site. Clearing of vegetation is prohibited within 75 feet horizontal distance of the shoreline. There shall be no cleared opening greater than 250 feet in the forest canopy.

Discussion Many non-compliant homes observed. Probably pre-date shoreland zoning ordinance. The Vassalboro Code Enforcement Officer expressed a concern about the lack of restrictions regarding converting seasonal residences into permanent residences.

Buffer Strips Absorb runoff to control nutrients entering the lake. A good buffer consists of several vegetation layers and a variety of plants and trees to maximize benefits. Natural vegetation form the best buffers. Riprap can also be used to protect shoreline erosion.

Buffer Strip Scoring Score determined according to lakeshore coverage, buffer depth and composition, slope, lot distance and need for riprap. Score range 1 – Poor 10 – 15 Partial 16 – 20 Adequate

Poor Buffer Good Buffer

Buffer Strip Quality Map of Webber Pond % for each categories Adequate: 28.1% Partial: 50.3% Poor: 21.6%

House Count Assess intensity of residential development in shoreline area and in the watershed as a whole. Identify and locate other land uses such as: farms, schools commercial buildings. Assess impact on nutrient loading of the lake.

ShorelineNon- Shoreline Total Seasonal Year- Round Unknown 310 House Count Data Total number of houses counted: 349 Other Buildings and landuse noted: - School - Farms - Golf Course - Boat Storage - Tree Farms - Orchard - Nursery

Subsurface Disposal Systems Must conform with State of Maine Wastewater Disposal Rules Minimum setback of 100 horizontal feet from the normal high water mark. Town of Vassalboro Ordinances

Town of Vassalboro Ordinances (continued) By December 31, 1995 all wastewater disposal systems in the Shoreland Zone must have: Provided documentation showing the existing system was installed after July 1, 1974 Or Installed a new system in compliance with State of Maine regulations

Webber Pond Watershed Subsurface Disposal Systems Almost all systems are septic systems, no holding tanks, one outhouse and one chem-toilet. State funding is used to help residents with cost of upgrading their system. Green Valley Campground uses several leach fields up hill from camp sites.

Roads Results and Discussion Roads create cleared areas that increase erosion and sedimentation while creating channels that direct nutrient rich runoff towards the lake. Poorly maintained camp roads present the largest environmental problem facing Maine watershed health. Road areas: acres of unpaved road, 27.5 paved Road ratings: 14 good, 13 acceptable, 10 fair, 6 poor and 1 very poor.

Road Survey Map

Intermission