Overcoming expansive soils with Tensar’s TriAx Geogrid

November 13, 2019

Expansion: it’s a win for communities when roads reach out and connect people to business, resources and formerly rural areas. But another form of expansion—soil that expands when water is added and shrinks when it dries out—can thwart this progress by making it hard to economically build and maintain long-lasting roads. “Expansive soil” is in …

Nature area drainage control with GCCM

October 1, 2019

By Joe Royer, Kurt Chirbas and Ziad Mazboudi The City of Laguna Niguel in Orange County, Calif., has its origins in the Rancho Niguel Mexican land grant, acquired in 1959 by the Laguna Niguel Corp. to develop one of California’s first master-planned communities, which has become predominantly a bedroom community. The city encompasses a total …

Lessons learned in alternative coal ash pond closure design and construction

By Anna M. Saindon Coal ash pond closures often face unique challenges due to location, available borrow soils and construction constraints. These challenges can lead to alternative methods of closure to comply with Resource Conservation and Recovery Act (RCRA) Subtitle D and coal combustion residuals (CCR) regulations. This article summarizes the construction of the first …

Remediation case study of uranium ore residues settling basin

September 30, 2019

By Laura Carbone, Ole Syllwasschy and Lilma Schimmel In the past, the Soviet-German stock company Wismut carried out an intensive uranium mining operation resulting in a large amount of polluted tailings containing daughter nuclides of uranium (Koß 1997) that were released into industrial sediment ponds (named IAA). The tailings “Pond 4” was built in 1957 …

An innovative cover system to close an ash/sludge impoundment

August 1, 2019

By Paul C. O’Malley, José L. Urrutia and Don DiGuilio The two projects (confidential client) are industrial sites consisting of coal ash and by-product sludge located in the southeastern United States. The projects included 70 and 67 acres (28 and 27 ha) in closure areas, and the waste source consisted of industrial sludge with a …

Reviving the Palos Verdes Reservoir—Part 4

By John Heap and Chris Kelsey The active site work for the Palos Verdes Reservoir’s substantial update began in late 2016, advanced primarily throughout 2018 and concluded in the second quarter of 2019 with the filling of the reservoir. The project was immense for everyone involved, and with that has come the expected excitement, challenges …

A minitube blanket for landfill gas collection and containment

By Stephan Fourmont, Pascal Saunier and Toraj Ghofrani Landfill gas (LFG) is produced during the decomposition of putrescible material in landfills. Often referred to as biogas, LFG is a source of odors and fugitive greenhouse gas (GHG) emissions. LFG is typically 40%–60% methane, which is 25 times more potent to affect climate change than carbon …

Stabilization of subgrade soils during Interstate 95 lane widening

By Bryan C. Gee, Eric Klein and William T. Maier The Maryland Transportation Authority (MDTA) is implementing a multiyear, multiphase project to add express toll lanes (ETLs) to Interstate 95. The ETLs are providing significant congestion relief in one of the most heavily trafficked corridors in the United States. The major modification to I-95 consists …

Streambank restoration using engineered bank stabilization

June 1, 2019

By Jeffery T. Hoilman and Stanley M. Miller Mountain Creek flows through the community of Red Bank near Chattanooga, Tenn., to the Tennessee River. Mountain Creek has been identified by the Tennessee Department of Environment and Conservation (TDEC 2018) as a 303(d)-listed stream, meaning that its pollution exceeds the state’s standards for one or more …

Carthage Mills installs geocell in video

May 2, 2019

Carthage Mills has released a YouTube video showing the installation of a geocell on a slope. The company carries the CX and CXW Series of geocells, which are three-dimensional, expandable panels made from high-density polyethylene (HDPE). Engineers use such geocells for containment, erosion control and ground stabilization applications. They improve the structural and functional behavior …