Southeastern Section, GSA Hydrologic Connectivity and Water Quality Function of Coastal Plain Geographically Isolated Wetlands March 25, 2011 Southeastern Section, GSA Amy Keyworth, NCDENR, Division of Water Quality Rick Bolich, NCDENR, Division of Water Quality

Background Wetlands contribute to water quality Clean Water Act, 1972 Prevent or control flash flooding ۰ Surface water pollution Erosion ۰ Loss of biodiversity Clean Water Act, 1972 2 Supreme Court decisions 2001 – Solid Waste Agency of Northern Cook County (SWANCC) 2006 – Rapanos/Carabell 2

Background Geographically isolated wetlands – no Federal protection “Significant nexus” to navigable waters Interpreted as surface water drainage Geographically isolated wetlands – no Federal protection Isolated wetlands serve most of the same functions as “connected” wetlands Habitat of amphibians that need fish-free environments to reproduce

Background No national policy - state by state protection NC adopted rules 2001 – new rules 2006 – strengthened rules Is groundwater a significant nexus? (you just can’t see it) 4

Objectives EPA funded grant project Estimate acreage of Isolated Wetlands lost and mitigated To determine the pollution absorption capacity and the water quality function of these systems To identify and characterize the hydrological connectivity to downstream water bodies

100 Miles 10 Miles 10 Miles Bladen County Brunswick County

Bladen County is covered in Carolina Bays, including several of our sites 1 Mile Bladen County

Brunswick County 1 Mile 10 Miles No Carolina Bays but perhaps an ancient scarp and plenty of sinkholes (don’t show up on map) Brunswick County

Data Collection 44 cores 72 monitoring wells 3 pumping wells Water levels monthly point-in-time 32 automatic data-loggers Adding stream gages 3 Aquifer tests Water quality Quarterly Nutrients Metals Other – TOC, DOC

Typical Site Core site 500 Ft Cored in wetland 4 points surrounding it streamside 500 Ft Core site

Typical Site Core site Monitoring Well 500 Ft Installed monitoring wells in a transect from the wetland to the stream Core site Monitoring Well 500 Ft

Typical Site Core site Monitoring Well Data Logger 500 Ft Installed automatic dataloggers in at least 3 wells – wetland, upland, streamside Core site Monitoring Well Data Logger 500 Ft

Typical Site Core site Monitoring Well Data Logger Pumping Well 500 Ft At 3 sites installed a pumping well to perform an aquifer test Core site Monitoring Well Data Logger Pumping Well 500 Ft

Site BL7 – Cross-section Monitoring well # PW1 1 3 6 7 8 60 55 50 45 40 35 30 25 Elevation (feet) 1,000 500 This is the “simplest” site – 25 feet of undifferentiated sand overlying a hard dark gray clay Often a gravel bed and wood chuncks at the base of the sand Distance (feet) Monitoring well Pumping well Core and Monitoring well Well screen Dark gray clay layer Sandy layer Water Level (August, 2010)

Site BL7 – Potentiometric surface 49.0 49.5 50.0 50.5 51.0 51.5 In all cases found that groundwater is flowing through the wetland from some higher elevation to the stream in seemingly unimpeded flow Monitoring well Water table contour 500 Ft

Site BL7 – Water Levels Taking monthly readings in all wells Indicate that all wells respond in a similar fashion

Site BL7 – Water Levels BL7-MW1S – daily ground-water levels

Other Findings One site surrounded by a hardpan 250 Ft

Other Findings Also found a paleochannel, drilled to 42 feet – hit clay in one but not the other Coastal Carolina University ran GPR around this site 250 Ft

Other Findings Red = surficial well Blue = confined 2 aquifers, one confined or partially confined Purple lines = shallow wells Blue lines = deep wells CCU did a GPR run around one of these sites Red = surficial well Blue = confined

Well # Elevation (feet) Distance (feet) 1 2 3 4 PW1 5 600 200 400 65 600 200 400 65 60 55 50 45 40 35 30 25 20 15 10

Conclusion Ongoing investigation Field work in NC complete May/June The 8 isolated Coastal Plain wetlands in NC are hydrologically connected Understanding of how these 8 systems interact with and connect to downstream water bodies Pollution absorption capacity or the water quality function of these systems Have not found evidence to support the meteor hypothesis of Carolina Bays

Acknowledgements EPA Cooperative Agreement Number CD 95415809 and CWA Section 106 NCDENR, DWQ, Wetlands Unit and Aquifer Protection Section Virginia Baker, Rick Bolich, Rick Savage, Ross Vander Vorste, Ray Milosh DWQ Groundwater Investigation Unit State match Bladen Lakes State Forest Turnbull Creek Educational State Forest The Nature Conservancy

Contact Information Email contacts: Amy.keyworth@ncdenr.gov Rick.Bolich@ncdenr.gov 24