Big Econ River Water Sampling

Orange County Environmental Protection Division (EPD) requested CPWG conduct 12 months of surface water sampling along a 3-mile stretch of the Econlockhatchee River (Big Econ River).  Our team’s goal was to collect and analyze samples from this section of the river to obtain water quality background data prior to construction of the proposed Lake Pickett North and Lake Pickett South subdivisions.  The Lake Paxton tributary lies within the land of these two proposed high-density developments and flows directly into the Big Econ River.  The Big Econ River (WBID 2991) in Orange County is currently impaired for Fecal Coliform and Mercury.  This study was important to understanding the river’s current water quality prior to the impact that thousands of septic tanks may have on the river.  Additionally, the sample collected at the county line provided Orange County knowledge of pollutant loadings to the river at the Seminole County line.

CPWG Environmental and Water Resource experts, along with TEAM Engineering, conducted monthly surface water samples over a 12 month period at four locations in the Big Econ River.  The discharge measurements were performed according to USGS, WRD standards as outlined in the Geological Survey Water-Supply Paper 2175 “Measurement and computation of Streamflow”. During each monthly monitoring event, field measurements of pH, temperature, conductivity, dissolved oxygen, turbidity, and ORP were conducted at 0.5-meter intervals from the surface to the river bottom.  A measurement of Secchi disk depth was performed at each site during each monitoring event.  Collected data was entered into the Orange County EPD Field Data Sheet.

The collected lake samples were analyzed for following parameters:

1. Alkalinity
2. Total Ammonia Nitrogen (TAN)
3. NOx (nitrite + nitrate)
4. Total Kjeldahl Nitrogen (TKN)
5. Particulate Nitrogen
6. Total Nitrogen
7. Orthophosphorus
8. Total Phosphorus
9. Particulate Phosphorus
10. Total Suspended Solids (TSS)
11. Chlorophyll a
12. Color
13. Sucralose