UST Site Risk Assessment

AES is an industry leader in the application of RBCA (Risk-Based Corrective Action) to UST sites. AES personnel have trained regulatory personnel and industry in various states, and have been active participants on various RBCA interest groups, including ASTM, TPH working criteria group, and the TNRCC.

Over the past year, AES has closed more sites than any other consultant in Texas using RBCA, obtained the first risk-based closure in Arkansas, closed a site using a surrogate risk assessment for TPH in Virginia, and successfully negotiated risk-based cleanup levels and remediation system shutdowns in other states.

The AES risk assessment process involves:

• Conferring with our clients to determine facility or site environment goals
  
• Utilizing existing data when possible
  
• Discussing the planned approach with the regulatory agencies
  
• Using non invasive, cost effective means to augment data (when necessary), including geophysics and cone penetrometer testing and sampling when practicable
  
• Identifying the chemicals of concern
  
• Determining the exposure pathways and dose including exposure frequency, duration, and uptake rate
  
• Compiling toxicity data, in particular, the reference dose values and slope factors
  
• Performing contaminant transport modeling of the soil, water, and air (if needed)
  
• Characterizing the risk according to EPA guidelines

Applied Earth Sciences, Inc./AES, Environmental Consultants, 7322 Southwest Frwy., Ste. 1000, Houston, TX 77074. Tel: 713-981-7140; Fax: 713-981-8821.