| Development |
| Jenna Morrison | ||
| Development Objectives |
| Maine Residential Shoreline Rules | ||
| Town regulations | ||
| Impact on the water quality of China Lake | ||
| Buffer Strip Survey | ||
| Watershed House Count | ||
| Septic Systems | ||
| Commercial Land Use | ||
| Remediation Techniques | ||
| Maine Regulations |
| Maine Residential Shoreland Zoning Act (1974) | |||
| 250 ft zone | |||
| Requirements: lot size, setbacks, buffer strips | |||
| Resource Protection Districts | |||
| 5 on China Lake | |||
| Non-conformance | |||
| pre-1974 development | |||
| Regulations are enforced by a Code Enforcement Officer | |||
| Town Policies |
| China | ||
| Regulations for septic system construction | ||
| Phosphorus control ordinance | ||
| Vassalboro | ||
| Replacement ordinance for pre- 1974 septic systems | ||
| Land around West Basin owned by KWD | ||
| Background: Development |
| Shoreline development activities impact water quality | ||
| Buffer strips slow nutrient and sediment runoff | ||
| Septic systems can contribute to nutrient loading | ||
| Commercial land use has the potential to add pollutants | ||
| Watershed House Count Survey |
| Method: shoreline and road survey | ||
| 63% of shoreline houses are seasonal | ||
| Concentrated septic system use during summer | ||
| 30.2 houses per shoreline mile | ||
| Subsurface Wastewater Disposal Systems |
| China Lake Septic Project produced by the Town of China and KWD (2005) | ||
| Pre- 1974 septic systems without permits are potentially contributing to nutrient loading | ||
| Buffer Strip Survey |
| Methods: evaluate each shoreline property | ||
| Category rating of effectiveness of buffer strips | ||
| Buffer Strip Results |
| 55% had less than 60 ft of shoreline | ||
| 61% had a 0-10 ft buffer depth | ||
| Heavy shoreline development | ||
| Few forested areas on East Basin | ||
| Slide 10 |
| Watershed Commercial Land Use |
| Impervious surface | ||
| Farming and forestry | ||
| Three schools | ||
| Gas stations have | ||
| contaminated soil | ||
| Garages/ repair shops | ||
| Smaller Issues | ||
| Salt and sand storage | ||
| Capped landfill and transfer station | ||
| Seasonal eateries | ||
| Remediation Techniques |
| Maintain vegetated buffer strip | ||
| Across entire lot and up to 75 foot depth | ||
| Several layers: trees, shrubs, ground cover | ||
| Maintain and replace septic systems | ||
| Monitor | ||
| Update town records of permits | ||
| Incentives to replace grandfathered systems | ||
| Low-interest loans available | ||
| Conscious commercial and residential development | ||
| Development and Road Survey |
| Jackie Rolleri |
| Watershed Development Projections |
| Residential Growth | ||
| Estimate: 250 houses will be built in both China and Vassalboro by 2015 | ||
| Larger house size increases nutrient loading | ||
| More septic systems, roofs, driveways, roads, etc. | ||
| China: about 36 of 512 total lots remain undeveloped | ||
| Watershed Development Projections |
| Commercial buildings increase by one per year in both China and Vassalboro | |
| New bridge linking I-95 to Route 3 | |
| China: plans for a Commercial Site Review Ordinance | |
| Road Survey |
| Methods | ||
| Measured: | ||
| Length | ||
| Width | ||
| Crown | ||
| Slope | ||
| Recorded | ||
| Problems: | ||
| Crown | ||
| Grade | ||
| Ditch | ||
| Water Diversion | ||
| Culvert | ||
| Road Survey |
| Crown | ||
| Allows proper drainage | ||
| Prevents deterioration of road surface | ||
| Grading | ||
| Process of smoothing and crowning a gravel road | ||
| Keep road edges smooth so water can flow off side | ||
| Road Survey |
| Ditch | ||
| Diverts water flow off road and away from body of water | ||
| U-shape, do not exceed depth:width ratio of 2:1 | ||
| Road Survey |
| Water Diversion | ||
| Water bar: ridge running diagonally across road | ||
| Rubber bar: divert water off sloping sections of a road while allowing traffic to drive over it | ||
| Road Survey |
| Culvert | ||
| Hollow pipes installed beneath roads to channel water in proper drainage patterns | ||
| Size: large enough to handle water at peak flow time | ||
| Road Condition Ranking |
| Road Condition Ranking |
| Road Assessment Results |
| Slide 24 |
| Problem Areas |
| Remediation Techniques |
| Roads | ||
| Maintain proper crown | ||
| Clear debris from culverts and ditches | ||
| Eliminate berms | ||
| Install water diversions where appropriate | ||
| Road associations | ||
| Phosphorus Model |
| Sarah Becker |
| Phosphorus Model: What is it? |
| Estimation of the total amount of phosphorus (P) entering the lake from: | ||
| Various external sources | ||
| Internal source = Sediment release | ||
| Mathematical model used to make: | ||
| Current estimates | ||
| Future predictions | ||
| Phosphorus Model: How is it Calculated? |
| Phosphorus Model: How is it Calculated? |
| W = total amount of P entering the lake in a year (kg/yr) |
| Phosphorus Model: How is it Calculated? |
| W = total amount of P entering the lake in a year (kg/yr) | |
| (Ec x Area) = amount of P from a particular land use type (kg/yr) |
| Phosphorus Model: How is it Calculated? |
| W = total amount of P entering the lake in a year (kg/yr) | |
| (Ec x Area) = amount of P from a particular land use type (kg/yr) | |
| Septic systems |
| Phosphorus Model: How is it Calculated? |
| W = total amount of P entering the lake in a year (kg/yr) | |
| (Ec x Area) = amount of P from a particular land use type (kg/yr) | |
| Septic systems | |
| Schools and residential summer camps |
| Phosphorus Model: How is it Calculated? |
| W = total amount of P entering the lake in a year (kg/yr) | |
| (Ec x Area) = amount of P from a particular land use type | |
| Septic systems | |
| Schools and residential summer camps | |
| Sediment release |
| Phosphorus Model: Results |
| Slide 36 |
| Slide 37 |
| Phosphorus Model: Implications and Conclusions |
| Best estimate from external sources and sediments: | ||
| W = 4843 kg/yr | ||
| P = 18.8 ppb | ||
| Threshold for algal blooms = 15 ppb | ||
| To lower phosphorus concentrations to 15ppb, W needs to be reduced to 3850 kg/yr | ||
| How? | ||
| Phosphorus Model: Implications and Conclusions |
| Taking measures to reduce external loading will help | |
| Sediments must also be addressed | |
| Example: |
| Phosphorus Model: Implications and Conclusions |
| To reach goal of 15 ppb, both external and internal sources must be addressed | ||
| External sources - to reduce the amount of new phosphorus that enters the lake each year | ||
| Sediment release - to reduce internal phosphorus cycling | ||
| Lake Remediation |
| Ethan Payne |
| Lake Remediation |
| Controlling phosphorus loading in China Lake is not easy | |
| In-lake remediation attempts to control internal phosphorus loading | |
| Land use and development trends will determine which techniques may be viable and which will not |
| Challenges for Remediation |
| Both internal and external phosphorus loading must be controlled | |
| Two townships and two basins | |
| High costs of in-lake treatments | |
| No guaranteed in-lake phosphorus management techniques |
| Physical Remediation Techniques |
| Dredging | ||
| Removal of sediment | ||
| Takes sediment phosphorus out of the lake | ||
| Hypolimnetic Withdrawal | ||
| Remove phosphorus-rich water from bottom | ||
| Hypolimnetic Aeration | ||
| Pump air or oxygen into the hypolimnion | ||
| Drawdown |
| Seasonal drop in water level every year | |
| Done at the time of the fall turnover | |
| Currently done in China Lake |
| Chemical Manipulation |
| Ferrous treatment | ||
| Iron complexes can form in presence of oxygen | ||
| Calcium treatment | ||
| Calcium carbonate salts dissociate and form phosphorus precipitate in basic water (pH > 9) | ||
| Algicides | ||
| Targets the algal cell growth | ||
| DoesnÕt remove phosphorus | ||
| Short-term fix | ||
| Alum Treatment |
| Aluminum sulfate forms phosphate complex | |
| Creates a layer on the sediment which stops phosphorus release | |
| Done over deepest parts of the lake | |
| Can last up to 15 yrs |
| Alum Treatment (conÕt) |
| Threemile Pond treatment was not effective | |
| Not enough alum applied to the deeper parts of the lake | |
| Disruption of the sediment from weather | |
| Using GPS and detailed bathymetry would be more efficient |
| Biological Manipulation |
| Aquatic Plant Harvesting | ||
| Remove phosphorus from water using vegetation, then remove the vegetation | ||
| Labor intensive | ||
| Fish stock manipulation | ||
| Increase populations of algae consumers | ||
| East Pond study | ||
| Suggested Lake Remediation |
| Alum treatment is the best way to combat internal phosphorus loading | ||
| Application needs to be carefully planned | ||
| Initial costs would be high, but a successful treatment could last 10 years | ||
| Summary |
| Caroline Polgar |
| Project Summary What Can We Do To Improve China LakeÕs Water Quality? |
| History of algal blooms indicates a water quality problem. | ||
| Phosphorus level high in the water column and sediments. | ||
| Sediment accounts for almost half of phosphorus in lake. | ||
| To effectively improve water quality, internal and external sources must be addressed. | ||
| Project Summary What Can We Do To Improve China LakeÕs Water Quality? |
| Suggestions to reduce phosphorus loading from external sources: | |||
| When developing the shoreline, consider lake water quality | |||
| Improve or create buffer strips | |||
| Maintain septic systems and roads | |||
| Use fertilizer responsibly on lawns and agricultural fields | |||
| Project Summary: What can we do to improve China LakeÕs water quality? |
| Internal sources of phosphorus must be reduced | |||
| Possible in-lake treatments include | |||
| Alum treatment | |||
| Sources of funding are available | |||
| Community Awareness and Education |
| What YOU can do to improve the water quality of China Lake | ||
| Post signs explaining the risks of introduced species | ||
| Get local students involved | ||
| Work together | ||
| SPREAD THE WORD! | ||
| Acknowledgements |
| Slide 57 |