Case Studies

Hydrofluoric acid tank cleaning and liner removal


Type: Confined space cleaning
Contract Value: $28,000
Period | Location: December, 2010 | Willoughby, OH
Work Areas: Level “B” OSHA PPE, tank cleaning, liner removal, QA/QC, sampling and analysis, health & safety planning, transportation & disposal, rigging, confined space entry, and work plan development.


EWMI was recommended to this Ohio based company by one of our current clients. This client had a tank that formerly contained 70% hydrofluoric acid. The acid compromised the 1/4-inch chlorobutyl liner within the tank so the client wanted the liner removed so the tank could be reconditioned and re-used.


EWMI mobilized our crew and equipment including OSHA Level “B” personal protective equipment, supplied air respirator (SAR) cascade air system with escape packs, breathing air cylinders and air hose lines, 4-Gas/PID meter, explosion proof lighting, ventilation blower, and other miscellaneous items (pressure washer, scaffolding).


To safely access the tank, a 30,000 pound forklift was used to position the tank so that man-way was at the optimal position. The atmosphere of the tank was checked and ventilated as required. EWMI removed the chlorobutyl liner and containerized the material for offsite transportation & disposal. The tank was cleaned with a 3,500-psi pressure washer.


EWMI managed all associated transportation & disposal for this project.

Former international chemical company site


Type: Excavation and disposal
Contract Value: $1,200,000
Period | Location: Late 2012-early 2013 (3 month project) | Northern New Jersey
Work Areas: Dig and haul, transportation and disposal


Several areas of concern (AOC’s) required remediation by the LSRP at this former site of a major international chemical company. EWMI was chosen from several bidders to manage the complete remediation activities for this Engineer/Consultant. Removal of a chain link fence, clearing and grubbing, installation of E&S controls, setting up of a dewatering and treatment system were all part of the initial mobilization tasks. Then excavation commenced by taking overburden soils (approximately 6 feet) and stock piling for re-use (approx. 3500 tons). Breaking and removal of concrete in a few areas also was required.


The AOC’s were then excavated to various depths up to 15 feet. Soils were stockpiled at the request of the engineer and sampled/analyzed for disposal characterization purposes. Benching/sloping methodologies were needed in some areas and Quadrant excavation was necessary along a drainage ditch. All areas were backfilled with Dense Grade Aggregate (DGA) with 12” lifts and a non-woven geotextile fabric placed between the stone and overburden soils. All soils were loaded, transported, and disposed: approximately 7500 tons total. General site clean-up, E&S control removal, replacement of fence, and other demobilization tasks were completed for final site completeness.

Reconstruction of environmental cap


Type: Remediation, transportation & disposal
Contract Value: $6-$9 Million
Period | Location: May 2014-current | Baltimore, MD
Work Areas: Capping & liner, excavation, transportation & disposal.


Excavation and reconstruction and alteration of an existing environmental cap. Surgical excavation through existing multi-media cap. Demolition of abandoned concrete foundations and footers. Transportation & Disposal over 15,000 tons of chrome contaminated soil and debris. Work side by side with pipe pile contractor and sheet pile system along the water front in Inner Harbor. Restore all synthetic layers and boot pipe piles with LLDPE. Replace fill around pile caps. Manage chrome contaminated groundwater.

Chemical manufacturer's lagoon/basin cleanout


Type: Remediation, transporation & disposal
Contract Value: $260,000
Period | Location: Summer 2012 | Central Delaware
Work Areas: Lagoon cleanout, dewatering, solidification, transportation and disposal


EWMI was selected from four (4) bidders to manage the complete removal of sediment from this lined lagoon (180 x 280 feet). This lagoon was at an active manufacturing plant with a constant flow of water coming into the basin. The water flow had to be isolated. The water in the lagoon was brought down as much as feasible via pumps. The liner at the bottom of the basin had to be protected throughout this entire sludge removal process.


First, EWMI had to remove an extensive amount of reeds/phragmites from the lagoon. This was difficult due to the intricate root system of this species. Once the reeds were extracted, the sediment and sludge at the bottom was carefully removed via excavators with attachments to “pull” sediment towards the perimeter of the lagoon. Vactor/supersuckers were also used in certain areas. The sediment was allowed to gravity drain as much as possible, then a system of drying agent/kiln dust was added to “set” the material for proper transportation and disposal at a non-hazardous subtitle “D” landfill. Approximately 600 tons of sediment from the lagoon/basin was removed, transported, and disposed.