Remediation of Arsenic‑Contaminated Soil and Groundwater
Confidential Golf Course Owner-Operator • Southeastern United States
Solution Overview
Client:
Confidential golf course owner-operator
Business Challenge:
- Elevated levels of arsenic found in soil and groundwater
- High voltage underground electrical utilities in the area
Solution:
- Careful coordination with Florida Power & Light (FPL) for source removal/soil excavation
- Implementation of engineering and institutional controls to address contaminated soil and shrink extent of arsenic in groundwater within the property boundaries
Results:
- Successful remediation during unrestricted closure of adjacent properties and conditional closure of the maintenance area
- Services conducted to date within client’s original budget and schedule
Challenge
Restoration of properties for new or altered use comes with many challenges. As new and virgin land in desirable locations becomes more scarce, savvy property developers will often look to decrepit, defunct, and contaminated sites as options for their projects. As such, skilled consultants are an essential partner to ensure that the condition of the site is restored to ensure adequate safe-guarding of both human health and sensitive environmental receptors. Arsenic is a common contaminant used historically on golf courses and in landscaping to prevent the growth of nuisance weeds and is also contained in some fertilizers. As such, many golf courses have been found to be contaminated due to the historical application of arsenic, especially in tee box areas and greens. Storage and mixing of arsenical herbicides has also resulted in the contamination of maintenance areas. A golf course owner operator in South Florida approached Apex Companies to help assess and remediate a former country club maintenance area in Lauderhill, Broward County, Florida. In this case, the owner-operator wanted to remediate the site, continue its use as a golf course, and ensure that conditions at the site were restored for any altered future use.
Solution
Drawing on our staff’s golf course remediation expertise, Apex conducted groundwater monitoring, site assessment, and developed a conceptual site model remedial design to determine arsenic contamination within and outside of property boundaries—the areas of the site that were most likely to have elevated levels of arsenic in soil and groundwater. Site assessment indicated the presence of arsenic in soil in concentrations greater than allowable limits; arsenic in soil extended onto the western adjacent property belonging to FPL’s Woodlands Substation.
Site assessment also indicated arsenic groundwater contamination to a depth of 65 feet that extended onto the eastern and western adjacent properties. Given the abundance of high voltage underground electrical utilities in the source removal/soil excavation area, Apex staff regularly interacted with FPL, especially for the soil remediation/source removal.
Based upon assessment data, Apex implemented source removal activities to remediate soil on the western adjacent property and used engineering and institutional controls to address soil on the golf course maintenance area property. Similarly, we designed a remedial approach to shrink the extent of arsenic in groundwater to within the maintenance area property boundaries. Groundwater remedial design consisted of the injection of an amendment designed to drive the aquifer to extreme reducing conditions to precipitate arsenic from groundwater with the introduction of iron and sulfate designed to form arseno-pyrite compounds. Apex performed two injection events and successfully remediated groundwater on the western adjacent FPL substation property but not on the eastern adjacent property where the size of the arsenic plume was much larger.
Results
Apex successfully implemented a combination of active remediation and engineering and institutional controls, as well as a remedial approach designed to provide unrestricted closure of adjacent properties and conditional closure of the maintenance area. Remedial activities were completed within budget and regulatory time frames.
Efforts to obtain closure of the eastern adjacent property using non-recorded institutional controls are ongoing. Apex has supported this effort with stormwater mounding and nearby irrigation well analysis.