GCI (Grace Consulting, Inc.) is one of the leaders in industrial air emissions ("stack") testing. Let us perform your HAPs/VOC's, CO2, NOx, Particulate, Visible Emissions testing, CEMS RATA's, and other source sampling to remain in EPA Compliance, re-certify your permit, and/or conduct investigative/engineering testing. With almost 25-years of experience, 50 employees, 18 mobile monitor laboratories, and multiple nation-wide offices to mobilize from, GCI has the experience and flexibility to meet your scheduling, budgetary, and compliance needs.