County of Louisa Water Quality Management Plan and Groundwater Study Prepared By: T/lOlllas Jeffersoll Plallnillg District COII/missiofl I'irgillia Divisioll of I'vlifleral Resollrces Louisa COUIII)' Plallfling Departlllel!1 Louisa Couflt)' Water Aut//Oir!)' Draper -Idell -hsociates lallllar\ 1l)l)X County of Louisa Water Quality Management Plan and Groundwater Study Prepared By: Thomas Jefferson Planning District Commission Virginia Division of Mineral Resources Louisa County Planning Department Louisa County Water Authoirty Draper Aden Associates January, 1998 Table of Contents Executive Summary 1.0 Introduction ................................................................................................................... 1-1 1.1 Objectives .................................................................................................................. 1-1 1.2 Potential Growth Areas .............................................................................................. 1-2 1.3 General Infonnation ................................................................................................... 1-2 1.4 HistorylBackground ................................................................................................... 1-4 1.5 Previous Reports and Infonnation ............................................................................. 1-4 2.0 Present Water Quality in Louisa County .................................................................... 2-1 2.1 Watersheds ................................................................................................................. 2-1 2.2 Groundwater Quality ................................................................................................. 2-1 2.2.1 Louisa County DRASTIC Study ................................................................ 2-3 2.2.2 Louisa County Water Testing Study .......................................................... 2-3 2.2.3 Evaluation of Household Water Quality in Goochland County ................. 2-4 2.2.4 Review ofVDH Data .................................................................................. 2-4 2.3 Surface Water Quality ................................................................................................ 2-5 2.3.1 Prioritization of Third and Fourth Order Watersheds ................................. 2-5 2.3.2 Chemical Data Analysis .............................................................................. 2-5 2.3.3 Biological Data Analysis ............................................................................ 2-8 2.4 Sanitary Drainfields ................................................................................................... 2-8 3.0 Geology and Groundwater Hydrology ........................................................................ 3-1 3.1 General Overview ...................................................................................................... 3-1 3.2 Bedrock Geology ....................................................................................................... 3-2 3.3 Saprolite ..................................................................................................................... 3-3 3.4 Soils ........................................................................................................................... 3-7 3.5 Water Well Database ................................................................................................. 3-9 3.6 Impacts of Mining on Water Quality ....................................................................... 3-15 4.0 Existing Water Supply and Wastewater Systems ....................................................... 4-1 4.1 Water Supply .............................................................................................................. 4-1 4.2.1 Surface Water ........................................................................................... 4-1 4.2.2 Groundwater ............................................................................................ 4-1 4.2 Wastewater Treatment Systems ................................................................................. 4-5 4.2.1 Louisa County Wastewater Treatment Plant .............................................. 4-5 4.2.2 Town of Louisa WWTP .............................................................................. 4-7 4.2.3 Private Wastewater Treatment Facilities .................................................... 4-7 4.2.4 Septic Tanks and Sanitary Drainfields ........................................................ 4-8 4.3 Existing Water and Wastewater Infrastructure .......................................................... 4-8 4.4 Existing Water and Wastewater Usage ...................................................................... 4-9 4.5 Existing User Fees ..................................................................................................... 4-9 5.0 Projected Water and Wastewater Demands ............................................................... 5-1 5.1 Projected 20 Year Demands Using Population Growth ............................................. 5-1 5.2 Projected 20 Year Demands Using Present Comprehensive Plan ............................. 5-4 5.3 Ultimate Demands Using Present Comprehensive Plan ............................................ 5-8 5.4 Ultimate Demands Based on Build-Out Housing Unit Density ................................ 5-8 6.0 Water System Evaluation For Future Growth ........................................................... 6-1 6.1 Future Regulations and Water ................................................................................... 6-1 6.2 Surface Water Sources ............................................................................................... 6-1 6.2.1 Northeast Creek Reservoir .......................................................................... 6-2 6.2.2 Lake Gordonsville ....................................................................................... 6-2 6.2.3 Direct Withdrawal from South Anna River ............................................... 6-2 6.2.4 New Surface Water Impoundments ............................................................ 6-3 6.3 Groundwater Resources in Potential Growth Areas .................................................. 6-3 6.4 Obtaining Water From Adjoining Counties ............................................................... 6-7 6.5 Water Storage Requirements ..................................................................................... 6-8 7.0 Wastewater System Evaluation For Future Growth .......•.......................................... 7-1 7.1 Future Regulations and Wastewater Treatment.. ....................................................... 7-1 7.2 Anticipated WWTP Discharge Requirements ........................................................... 7-3 7.3 Typical Wastewater Treatment Facility ..................................................................... 7-3 7.4 Wastewater Treatment for the Lake Anna Area ........................................................ 7-4 7.5 Upgrade of Louisa County Wastewater Treatment Plant .......................................... 7-5 7.6 Centralized WWTP for Louisa County ...................................................................... 7-5 7.7 Alternative Wastewater Treatment Systems .............................................................. 7-6 7.7.1 Cluster Systems ........................................................................................... 7-6 7.7.2 Enhanced Flow Systems ............................................................................. 7-6 7.7.3 Low-Pressure Systems ................................................................................ 7-6 7.7.4 Sand Filters ................................................................................................. 7-6 8.0 General Information ...................................................................................................... 8-1 8.1 Goal One: Protect and Maintain Water Quality in Louisa County ........................... 8-1 8.2 Goal Two: Protect the Groundwater Quality in Louisa County ............................... 8-8 8.2 Goal Three: protect water quality of the rivers and streams flowing through Louisa County .................................................................................................................. 8-11 8.3 General: strategies which cut across protecting rivers and streams, groundwater and streams ............................................................................................................... 8-12 9.0 Water and Wastewater Master Plan Development ....•.•..•...•..•.•..•...•..............•...•....... 9-1 9.1 Water System Master Plan ......................................................................................... 9-1 9.2 Wastewater System Master Plan ................................................................................ 9-2 9.3 Phases of Implementation .......................................................................................... 9-3 9.4 Modifications to Master Plans ................................................................................... 9-3 10.0 Cost Estimates for Public Water and Wastewater ................................................... 10-1 10.1 Zion Crossroads ..................................................................................................... 10-1 10.1.1 Zion Crossroads Budget Analysis ..........................................................