New Methuen Readiness Center Benefits From CULTEC Underground Storm Water System

The Massachusetts Army National Guard (MAARNG), stationed in Methuen, Mass., needed to redesign its existing Methuen Readiness Center to meet the MAARNG mission, readiness and training requirements. The facility was inadequate in size and did not meet the current Anti-Terrorism and Force Protection (AT/FP) requirements.

Redesigned by OMR Architects, the new Readiness Center consists of a 42,000-sq-ft, two-story facility that includes an assembly hall, administrative, training and support spaces, and kitchen and maintenance bays. In addition to the new building, the 5.5-acre site featured about 3.4 acres of military and civilian parking area.

When it came to designing a storm water management system for the project, Boston, Mass.-based Nitsch Engineering Inc. was faced with a number of onsite challenges, including land constraints, a 148-ft AT/FP site boundary setback and related standoff distances and proximity to nearby wetlands. Additionally, the project occurred within the 100-year flood plain of the Merrimack River.

As the redesigned site featured an increased number of impervious surfaces, the MAARNG storm water plan needed to limit the post-development rate of runoff from the site to no greater than pre-development levels. To achieve that, as well as solve the challenge of space constraints, the engineers selected the CULTEC Recharger 180HD underground chamber system. Specific to the MAARNG site, the system was designed to detain runoff on site during small storm events and retain it during larger storm events.

“Granted the limited space we had to work with and absence of a municipal connection, an underground solution was the only way to go,” said Anthony Donato, P.E., LEED A.P. at Nitsch Engineering Inc. “We know CULTEC as a reliable and economic solution. The arch chamber design ensures the system’s structural integrity and the heavy duty models work well in high traffic applications, as in this case where the system is located under the parking lot.”

The engineers used HydroCAD modeling software to design the storm water system; CULTEC also offers a free HydroCAD CULTEC edition that allows constructing basic watershed models of up to five nodes, including storage, runoff and routing calculations for the company’s chambers.

CULTEC offers a variety of chamber sizes to accommodate almost any site constraint, and its higher-profile Recharger series make optimal use of large storage capacities in a smaller footprint. The Recharger 180HD is 20.5 in. high, 36 in. wide and has a chamber storage capacity of 3.45 cu ft per linear ft.

To address the facility’s storm water runoff storage needs, the CULTEC retention and detention system provided 11,052 cu ft of storage. The project required 300 Recharger 180HD units, which were installed in a 6,530-sq-ft bed and backfilled with 573 tons of stone.

The CULTEC system installation began with excavating a bed, laying CULTEC non-woven polypropylene filter fabric along the sides and the bottom of the bed and then adding a 6-in. layer of crushed stone. The chambers were arranged in the bed, fed using CULTEC unique internal manifold feature, and covered with 6 in. of crushed stone and a layer of filter fabric. The entire system was installed in about two days.

Source: CULTEC