Defender Tank Covers from Environetics are custom manufactured from industrial-grade materials to fit the profile of a new or existing wastewater treatment tank or potable water tank. They contain volatile organic compounds at their source. Low-profile structurally supported covers minimize emission treatment volume to reduce the cost of air filtration equipment. That can help eliminate the ongoing expense of applying costly odor control chemicals through atomizer and misters. 815-838-8331; www.environeticsinc.com