Innovative Cover Design Construction Completed Successfully

Much of the remediation at RMA is clean-up and on-site disposal of hazardous waste.  In the U.S. there are strict requirements for how that waste is disposed and covered. Methods that use synthetic covers have been the accepted standard, but at RMA an innovative alternative cover system was developed by the Army, with detailed involvement by EPA including engineering support and technical analysis from PWT and geotechnical/civil engineering expertise from PWT partners Steve Dwyer and Jorge Zornberg under the leadership of Dorthea Hoyt. This innovative solution underwent eight years of design, testing, and negotiations with regulatory agencies, and construction of 453 acres of the “RCRA-equivalent Covers” was completed between 2005 and 2010.

The professional publication, Civil Engineering, published this paper in January 2011. See the published paper.

California Gulch- OU 11 Superfund Site

California Gulch OU11Leadville, Colorado:

PWT used value engineering and sustainable design to remediate toxic metal-contaminated soils in former mining sites near Leadville, Colorado. In operable unit 11 of the site, PWT managed an innovative environmental remediation project to treat and re-vegetate 150 acres of irrigated meadows pastureland and 18 acres of fluvial deposits that bordered approximately 3,000 feet of the Arkansas River.

The design incorporated a unique remediation process. It included the application of a lime-based amendment that is a by-product of sugar beet processing: the first large-scale application of this type of in-situ soil treatment. In order for this amendment to work, it was important to thoroughly incorporate the lime mixture into the contaminated soil. A state-of-the-art soil mixer was incorporated into the design, making the process more efficient. The time and cost savings for this value-engineered process allowed an expansion of two acres of treatment and covered the subsequent year’s costs. It also saved the energy and environmental pollution impacts of the traditional method of extensive soil removal.

This unique process is helping to create healthy soils that support the germination of new vegetation. Based on this data, the EPA is considering using the same method to treat the Clark Fork River NPL Site, a much larger site in Montana.

See an EPA report about California Gulch at

PWT’s GIS Road Warriors

In January 2010, the Federal Highway Administration and National Park Service Road Inventory Program took possession of a Pathrunner vehicle, built by Pathway Services – Tulsa, OK. This vehicle or van collects data on paved roads on National Park lands.  This data consists of highly accurate distance/GPS, HD video (think google streetview), and most importantly- the distress of the pavement for roads existing in National Parks.  The data collected is used on a local/park level for inventory and pavement distress levels as well on a national level for guidance in establishing funding levels for roads.

This vehicle is actually a base model Ford E-350 van that has had a significant amount of custom fabrication.  Three HD cameras work in tandem with the GPS and distance measuring instrument to allow for precise measurements from the video to be made.  The distress of the pavement is measured in three components, the roughness of the road or longitudinal profile, the rutting along the road or transverse profile, and the cracking/patching on the pavement.  The roughness and rutting are measured using the latest technology with lasers and cameras.  The cracking is measured with a high-powered camera illuminated by lasers (natural lighting is not consistent).  The pavement images are then post-processed to automatically detect cracking and severity of cracking.  All of three of these components of pavement distress go into a series of algorithm that will calculate a Pavement Condition Rating or PCR that is assigned at different levels of distance from a 0.02 mile/per route level all the way to park wide total level.

There are four PWT employees contracted by FHWA to perform a 2-fold process.  First to plan the park collection effort, execute the collection effort, and manage the data prior to sending to Pathway Services for post-processing of distresses.  Second, the quality assurance of the data after post-processing and prior to delivery to the park.  Mike Walker and Jeff Beal head up the collection processes, while Paul Poston and Jennifer McCollom are tasked with the quality control aspects of the project.