Part 144.3 of 40 Compilation of Federal Regulations (CFR) defines an Underground Injection Well (UIW) as, "any bored, drilled or driven shaft, or a dug hole whose depth is greater than that of its largest surface dimension." Said part continues to classify types of UIWs based on function. It identifies the following UIW codes:

• 5D2 - Storm Drain Water Wells
• 5D4 - Industrial Drainage Wells
• 5W20 - Industrial Process Water and Waste Water Disposal Wells
• 5X28 - Automatic Service Station Disposal Wells
• 5W31 - Septic Systems (well disposal)

Impact Environmental has developed underground injection well management plans to ensure compliance with applicable Federal, State, and County regulations.

Review of property records, interviews with the property manager/owner, and inspection of a property may give evidence to locations of underground injection wells (UIWs) during the performance of a Phase I Environmental Site Assessment.

If recommendations are made to confirm or refute the presence of the suspected inaccessible UIWs or to detect if known UIWs have impacted the surrounding soil during their use or operation, a Phase II Environmental Site Assessment will be performed. Ground penetrating radar (GPR) may be used to identify the exact locations of inaccessible UIWs. A Geoprobe will then be used to install soil borings within the confines of the inaccessible UIWs to determine whether the soil and/or groundwater has been impacted by their use. Accessible UIWs of concern may be sampled using a hand augering tool.

UIWs that are no longer in use (due to sewer hook-up, etc.) or that are found to have impacted their surrounding soil or groundwater should be properly remediated and/or abandoned in accordance with applicable Federal, State, and County regulations. Impact Environmental will contact regulatory agencies, select proper contractors, observe the remedial services, and collect soil samples, if necessary. Impact Environmental can also provide contaminated soil management if UIWs have impacted the surrounding soil.