Tetra Tech EC, Inc. is an internationally known and respected full-service consulting, A/E and remediation firm. Over the last two decades we have successfully completed thousands of relevant environmental cleanup assignments for government clients including USEPA, DoD, DOE, USFWS, NPS, BoR, USACE, and NASA and a variety of state DOTs and environmental agencies. Our staff of over 2,000 engineers, scientists, managers, constructors, and craft labor, ensures our capacity to provide comprehensive services for large or small, simple or complex projects.

The scope of this SIN includes, but is not limited to, excavation, removal, transportation, storage, treatment, and/or disposal of hazardous waste; preparation, characterization, field investigation, conservation and closure of site; containment, monitoring and/or reduction of hazardous waste sites; and support. For remediation of soil and groundwater contamination, Tetra Tech EC, Inc. offers a superior capability developed as part of our leading role in the investigation and remediation of the largest and most complicated federal sites in the nation. Tetra Tech EC, Inc.'s science, engineering, and remediation staff are integrated in an end-focused team that works toward site closure.

Tetra Tech EC offers unique capabilities in Ordnance and Explosives Remediation. Training areas, ranges, munitions manufacturing facilities, munitions disposal sites, military bases and even battle areas are often contaminated with dangerous munitions that inhibit or prevent the unrestricted use of land. Tetra Tech EC, Inc. provides a complete range of ordnance and explosives (OE) investigations, detection and removal services to government clients in the US and abroad. As a full service contracting firm, we are capable of taking a OE contaminated site through the entire decontamination process, from developing work plans and cost proposals, through conducting pilot and treatability studies, implementing full scale remediation, including OE detection, identification, and removal, O&M, site release and closure followed by final site restoration, in a timely, quality, cost-effective manner.

Tetra Tech EC, Inc.'s unique approach to OE removal relies on the extensive use of advanced technology to detect unexploded ordnance and differentiate it from all of the other metallic objects that may be in the ground. Our high tech approaches differentiate items which are likely to be OE from those which are unlikely to be OE, and thereby reduces the number of excavations - and the time and cost of excavations - by as much as an order of magnitude. This translates into substantial cost savings as well as assuring immediate removal of the items with the greatest potential to cause harm.

Substantial improvements in both effectiveness of unexploded ordnance removal and in cost reduction have been made possible by advances in the use of computer-aided systems to collect data and present images of the area to be cleared. These systems can be used effectively to "filter out" the signals from small pieces of metal that obscure the unexploded ordnance items, allowing the unexploded ordnance specialist to focus on the just those objects that are large enough to be unexploded ordnance items. Tetra Tech EC, Inc. uses state-of-the-art detection systems, based on magnetic and electromagnetic inductance, to detect metal items (and where radiation or signatures from nonmetallic objects are expected, other geophysical sensors). The field data is analyzed using proprietary software, which is capable of estimating the mass, and depth of anomalies and comparing the data collected with cataloged data from verified OE excavations from the same site and other sites. The software produces a map of the area showing all of the detected objects, and creates a "dig sheet" which lists their precise location and approximate mass and depth. The sites where suspect OE are located are marked with flags for accessing and identification during removal operations. A fraction of the sites are selected for 100% removals. This validates the effectiveness of geophysical methods in finding anomalies and the analytical software in differentiating OE from other items. The locations where OE are suspected (usually less than 10% of the total anomalies discovered) are excavated and any OE encountered removed or destroyed in-place.