HELIX Environmental Planning (HELIX) prepared a National Environmental Policy Act (NEPA) Environmental Assessment (EA) for a new training range at Marine Corps Base (MCB) Camp Pendleton in northern San Diego County. The facilities addressed by HELIX included the training range, control room/observation tower with environmental control, two-story sniper house with multiple fire positions, moving infantry and stationary target emplacements, two-story facade, known distance target carriages, a concrete pad (for portable toilets), a paved access road, and a parking area. The project required substantial grading of native habitat areas, including filling two small canyons and filling/redirecting waters of the U.S.

 
In addition to the EA, HELIX conducted plant community, vegetation, rare plant, and coastal California gnatcatcher surveys; completed a Clean Water Act jurisdictional delineation; and prepared a Biological Assessment pursuant to the federal Endangered Species Act. HELIX also evaluated potential impacts to the federally listed tidewater goby which, although not present in the proposed action area, was known to occur downstream.  Specifically, HELIX evaluated the potential sedimentation effects of the proposed action, including the extensive on-site grading and realignment of waters of the U.S. that traversed the site, coupled with the use of sedimentation basins and construction best management practices to minimize off-site sediment transport.