Urbanization Impact on the Nature of Dissolved Organic Carbon William C. Vesely, Timothy J. Callahan, and Vijay M. Vulava

Overview Introduction Objective: estimate the role of urbanization on dissolved organic carbon (DOC) in tidal creeks Hypothesis: urbanized DOC is different than a less developed similar system –DOC: concentration vs. form Methods Sampling Areas

What is Dissolved Organic Carbon? Group of over a million molecules including simple amino acids to complex humic acids Organic carbon that can pass through a 0.20 to 0.70 micron filter Can serve as an indicator of land-based runoff (Wikipedia)

Why should we be concerned? Water Cycle Mobility of Pollutants Carbon Cycle polwaste/nps/urban_f acts.cfm f/rooms/acme_sics/acme /how.html vatory.nasa.gov/ Features/

Natural SourcesUrban Sources Detritus Soil Organic Matter Kerogen Plankton and Algae Hydrocarbons from Human Activities Pesticides Pet Waste Waste Water Treatment Effluent rma.com/leaf-litter/ SUVA 254 : aromaticity of DOC

Field Methods Samples collected with ashed 1L amber bottles Environmental parameters were measured using a YSI 556 MPS Precipitation data collected from NOAA database

Water Sample Preparation & Analysis Filtered using a 0.70 µm filtration system and then acidified Carbon analysis on a Total Organic Carbon Analyzer Analyzed for aromaticity properties using the SUVA 254 method Aromatic: humic load of organic C

Sampling Areas Samples taken from May 2015 to March 2016 Developed sites taken during falling tide #Site IDSite Name 1BBCBig Bay Creek 2BCBull Creek 3FCFilbin Creek 4FC_HPFC_ Hendricks Park 5HBCHorlbeck Creek 6NCNoisette Creek 7WCWimbee Creek

Analyzing Urbanization Impact DOC quality (SUVA 254 values) GIS: geospatial analysis (land use: percent developed vs. DOC and percent wetlands vs. DOC) Impact of precipitation on DOC mobilization Big Bay Creek Watershed

DOC Levels Results #Site IDSite Name 1BBCBig Bay Creek 2BCBull Creek 3FCFilbin Creek 4FC_HPFC_ Hendricks Park 5HBCHorlbeck Creek 6NCNoisette Creek 7WCWimbee Creek Undeveloped Developed DOC  land cover, not land use

SUVA 254 Results Developed Undeveloped #Site IDSite Name 1BBCBig Bay Creek 2BCBull Creek 3FCFilbin Creek 4FC_HPFC_ Hendricks Park 5HBCHorlbeck Creek 6NCNoisette Creek 7WCWimbee Creek

Urbanization Impact Less land cover causing reduced aromatic properties Should see urbanization impact on functional groups R 2 =0.49 Developed Undeveloped

Wetland Impact Terrestrial input from wetland likely causing high SUVA values Need to determine controlling factors on DOC levels R 2 =0.65 Developed Undeveloped

Five Days Prior Rainfall for Surface Water Filbin and Noisette Creek Developed sites Impervious cover a major factor All Sites Winter months Precipitation diluting SUVA (?) R 2 =0.32 R 2 =0.51 Developed Undeveloped

Summary Terrestrial sources of carbon causing high levels of DOC at Wimbee and Bull Creek Hypothesis was inconclusive due to insufficient data Wetlands showing to be a major source of aromatic DOC  plant based

Future Work Digitize watersheds: impact of development, impervious surfaces, and manipulated streams Watershed basin area and slope, and watershed hydrology Analyze chemical functionality of DOC using 13 C-NMR

Acknowledgments Project supported by the College of Charleston’s URCA by SURF grant SU and the CofC geology department The work is indebted to assistance by Dr. Barbara Beckingham, Cheryl Carmack of CWK, South Carolina DNR, Katie Ellis, Austin Morrison, and Lea Richter

Questions?