DPS Use in Treating Wastewater During Transit System Extension Construction

Eric Bradley-1

Eric Bradley | March 30, 2018

See how HaloKlear’s treatment system processed 150-600 gallons of water per minute during the Santa Clara County transit expansion using the Dual Product System – keeping the project on schedule, in compliance and within budget.

The Project:

The San Francisco Bay Area Rapid Transit (BART) and the Valley Transit Authority (VTA) began construction of Phase I, the Silicon Valley portion, of the extension of the transit system into Santa Clara County project in April 2012. This first phase consisted of a 10-mile, two-station extension from Fremont to Berryessa district and included at-grade, above-grade, and below-grade travel. In the Berryessa district north of San Jose, below-grade excavation began and groundwater was present at approximately 10 to 20 foot depth. With heavy sedimentation (2,000-4,000 NTU) and hydrocarbon contamination, the groundwater required treatment to reach California permit requirements (< 5 NTU) before being discharged.

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The Solution:

HaloKlear worked to build a wastewater containment and treatment system that could process 150-600 gallons per minute for 10-24 hours per day. HaloKlear’s natural and biodegradable Dual Product System (DPS), consisting of LPB-2101 and LiquiFloc 3%, was used to remove the sediment from the groundwater. HaloKlear LBP-2101 and LiquiFloc 3% are green wastewater treatment flocculants. When used in combination, the natural flocculants capture suspended solids and form highly stable and strong bonds. The Dual Product System used with gravitational settling and a filtration system was able to drop the sediments and clarify the water to < 5 NTU. Additionally, the hydrocarbon contamination concentration was lowered to the acceptable benchmark designated by the permit.

 

The Results:

HaloKlear provided an eco-friendly solution for treating the groundwater during the BART expansion project, Phase I, in Santa Clara County, California. HaloKlear DPS created dense floc with great shear strength and low water content that settled very quickly, allowing solids to be efficiently removed from the water column. The added benefit of HaloKlear natural wastewater flocculants was their ability to remove the hydrocarbon contaminants from the water. HaloKlear effectively treated the high volume of groundwater to reach the required < 5 NTU regulations. Overall, the treatment system, powered by HaloKlear DPS, helped keep the BART expansion project on schedule, in compliance, and within budget.