Environmental Remediation and Engineering Construction Services

Air Sparging/VES
In cases where high concentrations of dissolved volatile organic compounds (VOCs) are present in groundwater within a high permeability media, air sparging has been successfully used to assist vapor extraction for soil and groundwater remediation. Air sparing volatilizes and removes VOCs within the vadose zone soils and groundwater beneath the site. Ambient air is forced through a system of diffusers that are installed in sections below the groundwater table. The effect of diffusing this forced air into the groundwater removes volatiles from the sorbed and dissolved phases, thereby providing treatment to both the soils and groundwater in the saturated zone. The entrained organics are carried by the air bubbles into the vadose zone where they are captured by the vacuum created by a soil vapor extraction (SVE) system and are conveyed to a vapor treatment unit. In addition to the physical mechanism of volatilization, sparging increases the concentration of dissolved oxygen in the groundwater creating an environment that is conducive to aerobic biodegradation. Waterstone has successfully used this method in sites where an assist to the VES was warranted.

Excavation and Disposal
Waterstone has completed excavation and disposal projects at a wide range of sites. Waterstone conducts all aspects of an excavation and disposal job including preparing work plans with slope, grading or shoring engineering designs if needed; obtaining permits; implementing emission control measures; and documenting emissions monitoring, waste profiling, loading, traffic control, transportation, disposal, backfilling, and compaction certification. Waterstone staff can evaluate the volume of impacted material, the type and concentrations of contaminants, availability of space, time constraints, soil conditions and the disruption of business to determine if excavation and disposal is the best remediation option to meet a client’s needs.

Thermal Desorption
Waterstone has utilized thermal desorption for remediation of petroleum hydrocarbons in soil, effectively reducing or eliminating the potential long term liability associated with the land filling of wastes. In remediation by thermal desorption, contaminated soil is first excavated and transported to one of several permitted local fixed-base facilities or, for sites with larger quantities and available space, a mobile unit may be practical. Low temperature thermal desorption effectively destroys petroleum hydrocarbons present in soil by passing the soil through a rotary kiln system to heat the soil up to 600°F. The hydrocarbons are released into a vapor stream and destroyed in an afterburner system at temperatures of 1700°F. The soil can be re-used as fill material at approved sites after confirmation sampling verifies that cleanup criteria have been met.