Soil Sampling Reports
10/16/2017 Harris County performed a Preliminary Surface Soil Sampling of River Terrace Park located at 16550 Market St., Channelview, Harris County, TX. The project, conducted in July 2017, consisted of collecting soil samples from three areas within the park (A, B and C). A background sample was collected from Rio Villa Nature Trail which is a heavily wooded park situated upstream of River Terrace. The samples were analyzed for 17 congeners of dioxins and furans. The laboratory values were used to calculate the toxic equivalencies (TEQs) of the soil samples based on the 2005 World Health Organization (WHO) Toxic equivalency factors (TEF). Based on these TEQs, the values were compared to the USEPA 2,3,7,8- TCDD Residential Soil Regional Screening Level (RSL) based on current USEPA non- cancer (nc) risk endpoint. The TEQs for soil samples collected ranged from 4.037 ng/kg to 17.614 ng/kg, which are below the USEPA (nc) RSL of 51 ng/kg for 2,3,7,8 TCDD. The background sample collected upstream was calculated as 3.899 ng/kg which was also below the USEPA (nc) RSL of 51 ng/kg.
View the Soil Sampling report here
1/15/2018 A Limited Surface Soil and Sediment Sampling Project was conducted at four Harris County Precinct 2 parks within a two mile radius of the San Jacinto River Waste Pits. Within a four day period, Hurricane Harvey brought approximately 50 inches of rain to Harris County which caused mass flooding and soil/ debris deposition. Subsequent inspections of the San Jacinto River Waste Pits Superfund Site (SJRWP) determined the temporary cap had been compromised exposing dioxin waste to the San Jacinto River Surface waters. The project was conducted post- Harvey to determine if the surface park soil and nearshore sediments were impacted by the dioxin release from the San Jacinto River Waste Pits Superfund Site.
Precinct 2 requested sampling at Meadowbrook Park, Michael Moncrief Park, Rio Villa Nature Trail and River Terrace Parks. Samples of soil and sediment were taken at each location and analyzed for dioxins which were then compared to United States Environmental Protection Agency (USEPA) clean up action levels and dioxin background numbers.
The four day timeframe sampling occurred November 3, 2017 to November 7, 2017. At each park, composite soil samples and grab sediment samples were collected in areas that were observed as covered with flood waters and flood sediment by Harris County Park officials. The surface soil results for 2,3,7,8- TCDD (dioxin) ranged from 4.613 ng/kg to 11.805 ng/kg which are below the USEPA Residential Soil Risk Cleanup Level (NC) of 51 ng/kg for dioxin. The sediment grab sample results ranged from 2.599 ng/kg to 7.942 ng/kg. The EPA's official record of decision (ROD) notes a dioxin sediment background of 7.2 ng/kg in the San Jacinto River. The ROD requires that the cleanup level of dioxins at the site and in the sediments be to be 30 ng/kg to comply with health-based risk factors. Sediment samples collected at/near the parks are well below this health based value and in most cases are below the determined sediment background value.
View the Surface Soil and Sediment Sampling report here
Well Water Sampling Reports 12/1/16 In response to residents' concern about the quality of their well water, Harris County conducted testing of residential drinking water wells in two project areas located in east Harris County, TX. The sampling areas chosen are approximately one mile east of the San Jacinto River Waste Pits Superfund Site in the communities of Lynchburg and San Jacinto Oaks. The sampling project included collecting and analyzing water samples from 101 private residential drinking water wells for a target list of compounds which included metals, volatiles, semi-volatiles, pesticides, PCB's, some additional dioxin variations, and general water quality parameters. The results were then compared to established drinking water standards (maximum contaminant levels or MCLs). The individual test results are indicative of the water quality at the property tested. View the Phase I report here 9/15/17 Similar to the Phase I Residential Drinking Water Well Sampling Project, Harris County conducted additional testing of residential drinking water wells in two project areas located in east Harris County, TX. The project areas chosen were mainly located along the east and west banks of the San Jacinto River in Channelview and Highlands, -Texas. The project consisted of collecting 45 residential water well samples and 1 background sample located upstream of the project areas. The samples were analyzed for 17 congeners of dioxins and furans The sample results were then compared to the established EPA drinking water standard (maximum contaminant level or MCL) for 2,3,7,8-TCDD a contaminant of concern at the San Jacinto River Waste Pits. The analytical results for the water wells sampled ranged from 0.280 pg/L to 1.951 pg/L. None of the water wells sampled exceeded the EPA MCL of 30 pg/L used for 2,3,7,8-TCDD. The individual test results are indicative of the water quality at the property tested. View the Phase II report here