Engineered Natural Systems (ENS)

Roux Associates is a nationally recognized leader in the design and implementation of sustainable “Green” ENS treatment technologies. Our award-winning ENS Group focuses on the application of these technologies to treat groundwater and surface water contamination, stormwater runoff, landfill leachate, contaminated soils and sediments and industrial/municipal wastewaters. Roux’s ENS designs operate passively, require little to no power, and thus reduce O&M requirements and costs.

 
Technologies

Constructed Treatment Wetlands

Phytoremediation


Natural Media
Filtration



Applications

Wastewater
Treatment

Landfill
Closure


Stormwater
Treatment


Landfill Leachate
Treatment


Groundwater
Remediation

TMDLs



Wastewater Treatment

Phytoremediation Wastewater Treatment

Location: Rhode Island

A pilot 1-acre phytotechnology spray field was installed in 2003 to consumptively utilize process wastewater from an active manufacturing facility. Based upon the success of the pilot plot, a full scale 13-acre plot was installed in 2009.

Wastewater Treatment

Constructed Treatment Wetland Wastewater Treatment

Location: West Virginia

Designed and installed a CTW for the passive treatment of sanitary sewage from the 102 residential lots (total wastewater flow = 21,420 gpd). Effluent from home owner individual septic tanks flows to two parallel subsurface flow CTW cells for secondary sanitary sewage treatment.

Wastewater Treatment

Constructed Treatment Wetland Wastewater Treatment

Location: South Carolina

A pilot constructed treatment wetlands (CTW) system was installed in 2003 which handles approximately 10 gpm and is successfully treating stormwater runoff from an active manufacturing facility. Phytotechnology was evaluated for treatment of process lagoon water through consumptive use. Based upon the success of the pilot plot, a full scale 13-acre plot was installed in 2009.

Wastewater Treatment

Constructed Treatment Wetland Wastewater Treatment

Location: Pennsylvania

Designed a sustainable, cost effective sanitary wastewater treatment system to replace a failing 30 year old WWTP. Patented enhanced subsurface flow constructed treatment wetland designed to treat 60,000 gpd of sanitary wastewater from a technical campus.

Wastewater Treatment

Constructed Treatment Wetland Wastewater Treatment

Location: Saudi Arabia

The 23-acre Engineered Natural System (ENS) was designed and installed to treat 1.4 million gallons per day of wastewaters (sanitary, process and stormwater) generated from a 3,000 acre aluminum facility.

Landfill Closure

Phytoremediation Landfill Closure

Location: Virginia

A cost effective alternative landfill cover and leachate treatment system for a multi-national chemical company. Key design elements included: Constructed Treatment Wetlands (CTW) for pH neutralization and metal removal from leachate and a Phytotechnology cap in place of the traditional RCRA cap to capture stormwater runoff.

Landfill Closure

Phytoremediation Landfill Closure

Location: New Jersey

Completed the engineering design, construction support and operation and maintenance (O&M) for a 20-acre alternative cover system for a waste oil processing storage and disposal facility/Superfund Site. The design consisted of approximately 6 to 24 inches of soil cover, 13,000 hybrid poplars, cool season grasses and minimal structural drainage components.

Landfill Closure

Phytoremediation Landfill Closure

Location: Michigan

Installed over 4,000 hybrid poplars to minimize infiltration of precipitation into two inactive landfill cells. The plot was also designed to intercept and evapotranspire groundwater up- gradient of the landfill to minimize exposure of groundwater to landfill waste and protect down-gradient water resources.

Stormwater Treatment

Natural Media Filtration Stormwater Treatment TMDLs

Location: Virginia

Designed and constructed an anaerobic Natural Media Filter (NMF) for zinc removal from stormwater runoff generated from a former manufacturing facility. The NMF consists of vertical down-flow compost based filters designed to operate anaerobically to promote metal sulfide precipitation reactions.

Stormwater Treatment

Constructed Treatment Wetland Stormwater Treatment

Location: Iceland

Engineered Natural System (ENS) designed to treat stormwater runoff from a 200-acre metal smelter. The ENS collects stormwater runoff from production/industrial areas and provides pretreatment via vegetated swales and engineered soil profiles. Water is then conveyed to two CTWs for detention and treatment prior to discharge to the fjord.

Stormwater Treatment

Constructed Treatment Wetland Stormwater Treatment

Location: New York

Surface flow CTW designed to improve base-flow water quality, detain and treat stormwater runoff and reduce sediment transport during first flush storm events from a 12.4 square mile watershed. The CTW consists of sedimentation forebays, shallow marshes, and open water ponds for water quality improvement, but also includes the creation of tree islands for habitat preservation.

Stormwater Treatment

Constructed Treatment Wetland Stormwater Treatment

Location: New Jersey

Designed and constructed a surface flow CTW for the passive treatment of stormwater runoff generated from a scrap metal recycling facility. Stormwater runoff gravity drains via the existing storm sewer into two CTWs composed of forebays, ponds, shallow marshes and micropools.

Stormwater Treatment

Constructed Treatment Wetland Stormwater Treatment

Location: Texas

Designed a multi-faceted Engineered Natural System (ENS) to minimize annual maintenance costs for an international ore refining and metals processing company. The treatment system included an 8-acre constructed treatment wetland, vegetated bioswales, and an additional 8-acre sprayfield to reduce erosion, eliminate flooding, provide treatment, and promote zero discharge.

Stormwater Treatment

Constructed Treatment Wetland Stormwater Treatment

Location: New York

Designed a stormwater treatment wetland to manage and treat the runoff from a former municipal landfill. Stormwater runoff from the landfill is captured by a network of catch basins and conveyed to a series of 2 sediment forebays, followed by a shallow marsh and a polishing micropool.

Landfill Leachate Treatment

Constructed Treatment Wetland Landfill Leachate Treatment

Location: Virginia

Roux Associates is assisting a national insurance carrier by conducting an evaluation of environmental costs and liabilities at the Port of Seattle's historic Terminal 91 and Smith Cove. Our efforts have included review of past environmental response costs, identification of Responsible Parties from the Terminal's 120 years of operation, and allocation of investigation and remediation costs amongst the responsible parties.

Groundwater Remediation

Phytoremediation Groundwater Remediation

Location: Rhode Island

Risk based closure design to address free product, petroleum residuals, soil contamination, and dissolved phase groundwater impacts within a 100-acre former refinery. The key elements consisted of excavation, consolidation, and construction of a phytotechnology cover (15,000 trees) to promote rhizodegradation of residual organics, phytostabilization of metals, and hydraulic control of impacted groundwater.

Groundwater Remediation

Constructed Treatment Wetland Groundwater Remediation

Location: Rhode Island

Pilot subsurface flow CTW designed to passively intercept and treat the BTEX contaminated groundwater discharging to surface water at the site. The system's high aesthetic, low visual impact appeal was ideal for its golf course setting. Based upon the exceptional performance of the pilot system, a full scale CTW was designed and will be installed.

TMDLs

Natural Media Filtration TMDLs

Location: Indiana

Designed and constructed vertical flow compost based natural media filters (NMF) for the removal of low-level PCBs and TSS from facility stormwater. NMF technology has been instrumental to comply with its PCB discharge limit, and realize a savings of 86% in capital cost, as well as, 90% in annual operating cost when compared to conventional treatment alternative.

TMDLs

Natural Media Filtration Stormwater Treatment TMDLs

Location: Virginia

Designed and constructed an anaerobic Natural Media Filter (NMF) for zinc removal from stormwater runoff generated from a former manufacturing facility. The NMF consists of vertical down-flow compost based filters designed to operate anaerobically to promote metal sulfide precipitation reactions.

Constructed Treatment Wetlands

Constructed Treatment Wetlands (CTWs) are currently being used world-wide for efficient and cost-effective treatment of a variety of wastewater effluents with complex contaminants (e.g., BTEX, PAHs, metals, and CVOCs). Roux Associates has been actively involved in developing and applying CTW technology since 1993. Our use of carefully selected media, sequencing, and passive hydraulic controls have resulted in state-of-the-science 4th generation designs that are cost-effective, reliable and sustainable even under extreme environmental conditions.

Constructed Treatment Wetlands

Constructed Treatment Wetland Stormwater Treatment

Location: New York

Surface flow CTW designed to improve base-flow water quality, detain and treat stormwater runoff and reduce sediment transport during first flush storm events from a 12.4 square mile watershed. The CTW consists of sedimentation forebays, shallow marshes, and open water ponds for water quality improvement, but also includes the creation of tree islands for habitat preservation.

Constructed Treatment Wetlands

Constructed Treatment Wetland Stormwater Treatment

Location: New Jersey

Designed and constructed a surface flow CTW for the passive treatment of stormwater runoff generated from a scrap metal recycling facility. Stormwater runoff gravity drains via the existing storm sewer into two CTWs composed of forebays, ponds, shallow marshes and micropools.

Constructed Treatment Wetlands

Constructed Treatment Wetland Stormwater Treatment

Location: West Virginia

Designed and installed a CTW for the passive treatment of sanitary sewage from the 102 residential lots (total wastewater flow = 21,420 gpd). Effluent from home owner individual septic tanks flows to two parallel subsurface flow CTW cells for secondary sanitary sewage treatment.

Constructed Treatment Wetlands

Constructed Treatment Wetland Groundwater Remediation

Location: Rhode Island

Pilot subsurface flow CTW designed to passively intercept and treat the BTEX contaminated groundwater discharging to surface water at the site. The system's high aesthetic, low visual impact appeal was ideal for its golf course setting. Based upon the exceptional performance of the pilot system, a full scale CTW was designed and will be installed.

Constructed Treatment Wetlands

Constructed Treatment Wetland Stormwater Treatment

Location: Texas

Designed a multi-faceted Engineered Natural System (ENS) to minimize annual maintenance costs for an international ore refining and metals processing company. The treatment system included an 8-acre constructed treatment wetland, vegetated bioswales, and an additional 8-acre sprayfield to reduce erosion, eliminate flooding, provide treatment, and promote zero discharge.

Constructed Treatment Wetlands

Constructed Treatment Wetland Wastewater Treatment

Location: South Carolina

A pilot constructed treatment wetlands (CTW) system was installed in 2003 which handles approximately 10 gpm and is successfully treating stormwater runoff from an active manufacturing facility. Phytotechnology was evaluated for treatment of process lagoon water through consumptive use. Based upon the success of the pilot plot, a full scale 13-acre plot was installed in 2009.

Constructed Treatment Wetlands

Constructed Treatment Wetland Stormwater Treatment

Location: New York

Designed a stormwater treatment wetland to manage and treat the runoff from a former municipal landfill. Stormwater runoff from the landfill is captured by a network of catch basins and conveyed to a series of 2 sediment forebays, followed by a shallow marsh and a polishing micropool.

Constructed Treatment Wetlands

Constructed Treatment Wetland Landfill Leachate Treatment

Location: Virginia

A cost effective alternative landfill cover and leachate treatment system for a multi-national chemical company. Key design elements included: Constructed Treatment Wetlands (CTW) for pH neutralization and metal removal from leachate and a Phytotechnology cap in place of the traditional RCRA cap to capture stormwater runoff.

Constructed Treatment Wetlands

Constructed Treatment Wetland Wastewater Treatment

Location: Pennsylvania

Designed a sustainable, cost effective sanitary wastewater treatment system to replace a failing 30 year old WWTP. Patented enhanced subsurface flow constructed treatment wetland designed to treat 60,000 gpd of sanitary wastewater from a technical campus.

Constructed Treatment Wetlands

Constructed Treatment Wetland Wastewater Treatment

Location: Saudi Arabia

The 23-acre Engineered Natural System (ENS) was designed and installed to treat 1.4 million gallons per day of wastewaters (sanitary, process and stormwater) generated from a 3,000 acre aluminum facility.

Phytoremediation

Phytotechnologies are the use of vegetation for the in situ treatment of contaminated media (e.g., groundwater, surface water, soils and sediments). Also termed “Nature’s Pump and Treat,” it is a rapidly evolving passive technology that is gaining widespread support as an alternative to more costly conventional approaches, while also facilitating carbon sequestration. Roux Associates has amassed over 15 years of phytoremediation experience, with over 70,000 trees installed for a variety of functions.

Phytoremediation

Phytoremediation

Location: New Jersey

Completed the engineering design, construction support and operation and maintenance (O&M) for a 20-acre alternative cover system for a waste oil processing storage and disposal facility/Superfund Site. The design consisted of approximately 6 to 24 inches of soil cover, 13,000 hybrid poplars, cool season grasses and minimal structural drainage components.

Phytoremediation

Phytoremediation Landfill Closure

Location: Virginia

A cost effective alternative landfill cover and leachate treatment system for a multi-national chemical company. Key design elements included: Constructed Treatment Wetlands (CTW) for pH neutralization and metal removal from leachate and a Phytotechnology cap in place of the traditional RCRA cap to capture stormwater runoff.

Phytoremediation

Landfill Leachate Treatment

Location: California

Roux Associates designed, permitted and installed 1,700 hybrid poplars at an active sanitary landfill to consume an estimated 30,000 gallons of leachate per day. The tree plot is a sustainable approach for leachate management that provides passive and low cost treatment and eliminates the need for an on-site treatment plant or trucking of leachate off-site.

Phytoremediation

Phytoremediation Landfill Closure

Location: Michigan

Installed over 4,000 hybrid poplars to minimize infiltration of precipitation into two inactive landfill cells. The plot was also designed to intercept and evapotranspire groundwater up- gradient of the landfill to minimize exposure of groundwater to landfill waste and protect down-gradient water resources.

Phytoremediation

Phytoremediation Groundwater Remediation

Location: Rhode Island

Risk based closure design to address free product, petroleum residuals, soil contamination, and dissolved phase groundwater impacts within a 100-acre former refinery. The key elements consisted of excavation, consolidation, and construction of a phytotechnology cover (15,000 trees) to promote rhizodegradation of residual organics, phytostabilization of metals, and hydraulic control of impacted groundwater.

Natural Media Filtration

A Natural Media Filter (NMF) is a recent innovation designed to remove contaminants from water. NMFs are compost or peat based systems designed to remove and sequester heavy metals, oils, greases, nutrients, and organics from various wastestreams. NMFs utilize geochemical reactions to remove contaminants, without the addition of chemical reagents, through filtration, absorption and chemical transformation. The performance of NMFs constructed by Roux Associates for PCB removal has been excellent to date, with sustained PCB removals to levels well below 100 parts per trillion (ppt).

Natural Media Filtration

Natural Media Filtration TMDLs

Location: Indiana

Designed and constructed vertical flow compost based natural media filters (NMF) for the removal of low-level PCBs and TSS from facility stormwater. NMF technology has been instrumental to comply with its PCB discharge limit, and realize a savings of 86% in capital cost, as well as, 90% in annual operating cost when compared to conventional treatment alternative.

Natural Media Filtration

Natural Media Filtration Stormwater Treatment TMDLs

Location: Virginia

Designed and constructed an anaerobic Natural Media Filter (NMF) for zinc removal from stormwater runoff generated from a former manufacturing facility. The NMF consists of vertical down-flow compost based filters designed to operate anaerobically to promote metal sulfide precipitation reactions.

Natural Media Filtration

Landfill Leachate Treatment

Location: Virginia

Roux Associates designed and installed a natural media filter for the passive treatment of metal laden landfill leachate. Leachate flows horizontally through a compost based filter that is designed to remove metals from solution through microbial respiration and chemical precipitation processes. The system was installed in 2000 and has been consistently neutralizing pH and removing zinc from over 200 mg/L to less than 0.05 mg/L.

Enhanced Wastewater Treatment Wetlands