Cisterns for Stormwater Reuse and Runoff Reduction

Low Impact Development strives to eliminate runoff by promoting infiltrating wherever practical. If your site has high groundwater, soils with low permeability, bedrock, or other limiting conditions, infiltration alone may not provide enough runoff reduction to meet regulations. That’s why rainwater harvesting is an important tool to help meet runoff reduction requirements.

The DuroMaxx Rainwater Harvesting Cistern will help achieve stormwater management goals by reducing stormwater runoff while providing residual cost savings through the reduction of potable water use.

DuroMaxx Rainwater Harvesting Cisterns

DuroMaxx SRPE
The DuroMaxx Rainwater Harvesting Cistern is made from DuroMaxx Steel Reinforced Polyethylene (SRPE). The eighty (80) ksi steel reinforcing ribs provide the strength and pressure rated polyethylene (PE) resin provides the durability. The combination of materials results in an extraordinarily strong and durable below ground cistern.

• Available up to 120” diameter
• Includes prefabricated access points
• Lightweight - easily handled and quickly installed, often without the use heavy construction equipment
• H-25 traffic rated design

Contech’s DuroMaxx Rainwater Harvesting Cisterns have been certified to be in compliance with the Uniform Plumbing Code (UPC^®) by The International Association of Plumbing and Mechanical Officials (IAPMO) Research and Testing. Engineers can now write specifications for rainwater harvesting tanks based on a nationally recognized standard that address issues such as structural design, leakage, and repeatable manufacturing processes. Contech is only one of two companies that have received IAPMO/UPC certification for rainwater harvesting tanks.

Rainwater Harvesting Pretreatment Devices

Pretreating stormwater prior to storage protects downstream pumps, filters, and fixtures from damage or clogging, and lowers cleaning and maintenance costs by keeping pollutants out of the cistern and mechanical system. Contech offers a number of pretreatment devices including:

Downspout Filter
The Downspout Filter is the industry’s leading solution for treatment of roof runoff. The Downspout Filter removes and retains debris, metals, 93% of TSS, and 87% of hydrocarbons. This technology is used to treat commercial and industrial rooftops along with high rise buildings, parking structures, and residential buildings. Available in four sizes, this filter can easily adapt to downspouts 2” to 10” diameter. 

CDS
The CDS hydrodynamic separator is the preferred rainwater harvesting pretreatment device. CDS is an underground stormwater treatment device that uses swirl concentration and continuous deflective separation to screen, separate and trap trash, debris, sediment, and hydrocarbons from stormwater runoff.  With CDS there is no need for “first flush” diversion, so no water is wasted. 

CDS captures and retains 100% of floatables and neutrally buoyant debris 2.4mm or larger and removes solids down to 100 microns. It is the only non-blocking screening technology available in a hydrodynamic separator. With large pollutant storage capacity and treating flowrates up to 1 cfs, the CDS can treat runoff from large areas with minimal maintenance.