Frequently Asked Questions

How much do the StormTech chambers cost?

The price varies by region, as the cost of stone, fuel, excavation, and labor varies through the country and internationally. Please contact your local representative for relevant pricing in your area.

Where can I buy StormTech chambers?

Advanced Drainage Systems (ADS) sales staff and distributors are authorized to sell StormTech products. Please contact your local representative for distributors in your area.

What is an Isolator Row?

The Isolator Row is a row of StormTech chambers that is completely encased in geotextile filter fabric and acts as a sediment trap. A strip of woven geotextile is placed under the entire length of the row between the chambers and base stone. This provides a "floor" to the row that will allow water to pass, but will trap sediment and debris. A strip of non-woven geotextile is wrapped over the top of the chambers for the entire length of the row, separating the chambers from the cover stone, providing further filtration as the row fills. The Isolator Row should be the first row in the chamber bed at each inlet point. They must be directly connected to a manhole, catch basin, or other access structure. Small storm events and the first flush of larger storms (which carry the most debris) are directed into the Isolator Row first via a weir plate in the access structure or through elevation differences in the manifolds. Only when the Isolator Row fills does the water build enough of a head to top the weir plate, or reach the manifold invert to the standard rows. This overflow option provides a way to fill the system quickly during large storm events.

How do I connect the chambers? Do I need special tools?

The chambers are fitted together by overlapping the last corrugation. The chambers have arrows and notes molded into the top of the chamber to guide installers. No special tools, screws, fasteners, glue, etc. is necessary. Two people can easily move the chambers into place, and the weight of the surrounding stone and fill ensures the chambers will remain in place once backfilled.

Can I stack the chambers to create a layered system?

No. Unfortunately, the level of precision required to install a stacked system without creating a weak point in the system is very difficult to achieve. As a safety precaution, StormTech advises against the layout of stacked system. A stacked system will void the warranty.

Can the system be designed without infiltration?

Yes. When the soil conditions on site or regulations prevent infiltration, the chamber system can be used with a thermoplastic liner. The liner can be used under the entire chamber bed, wrapped completely around the chamber bed, or used under a portion of the chamber bed to slow/direct infiltration away from a sensitive area. The liner will need to be sandwiched between two layers of non-woven geotextile. The liner provider is responsible for the design and water-tight guarantee of their liner product.

How do I clean/maintain a StormTech chamber system?

A StormTech chamber system can only be cleaned when Isolator Rows are in use. Isolator Rows must be directly connected to a manhole, catch basin, or other access structure. The Isolator Rows can be cleaned with Jet-Vac equipment. The jet nozzle is sent down the Isolator Row and it washes the sediment trapped in the Isolator Row back to the access structure. The vac hose can then remove the sediment from the structure. StormTech recommends cleaning the Isolator Row when three inches of sediment has built up on the filter fabric. The sediment levels can be monitored through the inspection port, but cannot be cleaned through the inspection port. In beds with Isolator Rows longer than 150', additional access structures are recommended for ease of cleaning. View the Isolator Row O & M Manual.

What vehicles can I use over the system?

The StormTech chambers are designed for the current AASHTO design vehicle which adds load factors to the HS20 vehicle.When the structural design of the chambers is in accordance with AASHTO 12.12, structural adequacy can be presumed for a wide range of street legal vehicles and axle configurations. During construction, the acceptable vehicle loads over the system vary depending on the amount of cover over the system, and if paving has been completed. Since construction vehicles have many options & configurations, it is best to evaluate each vehicle individually. Please see our Acceptable Vehicle Loads to determine the ground pressure of your vehicle and what conditions are required.

There are two kinds of geotextile fabric called out - where do they go?

Non-woven geotextile is used as a boundary between the soil/stone interface to line the entire system. It should line the excavated pit and sidewalls during installation. The fabric should overlap by at least 2' wherever sections of fabric meet. Non-woven geotextile is also used to cover the Isolator Row chambers.The fabric wraps over the top of the chambers for the entire length of the Isolator Row, separating the chambers from cover stone. Woven geotextile is used between the chambers and the base stone only. A strip of woven geotextile should run the entire length of the Isolator Row, between chambers and base stone. At standard rows connected to an inlet manifold, a minimum of 12.5 feet of woven fabric should be placed under the first few chambers.

Can I connect a pipe through the side of the chamber?

No. All pipe connections need to be made through the endcap. To pierce the sidewall of the chamber would weaken the chamber and compromise the strength of the system. The endcaps can be ordered pre-fabricated with pipe fittings, or cut in the field to accept a pipe connection. Guides for common HDPE pipe sizes are molded into the endcap. Cutting into the sidewall of the chamber will void the warranty.

How do I model the chambers in my software program?

StormTech chambers use a stage-discharge methold similar to a surface pond. Underground storage chambers have been integrated into several stormwater modeling programs. StormTech has stage-area and stage-volume spreadsheets that can be downloaded and modified for your specific project. This data can be entered into most software programs to develop the stage-discharge relationship. Please see our Software Partners page for instructions and stage storage spreadsheets. If you need further assistance, please contact Technical Services.