In 2009 I wrote a blog piece about the new EPA rules promulgated for the hospital, medical, and infectious waste incinerator (HMIWI) maximum achievable control technology (MACT) standard. The compliance dates for these rules are fast approaching. Facilities with existing equipment must demonstrate compliance to the new standards by October 2014. Envitech is already under contract with several facilities to retro-fit existing medical waste incinerator scrubbers with add-on control equipment to meet the new standards.
The emissions reduction challenge with the new rules can be seen in the adjacent graph which compares the difference between the 2007 MACT standard to the new MACT standard. Stack emissions must meet substantially lower limits for Cd, Pb, and Hg. In many cases, this requires add-on controls capable of greater than 90% removal of sub-micron condensed metals. Most facilities are putting on a re-heat and filter package to remove the condensed metals. A few will use wet electrostatic precipitators (WESP) which are more expensive. The ability to meet the new rules using a re-heat and filter package has been demonstrated for lead and cadmium on a commercial and industrial waste incinerator (CISWI). The WESP capability has been demonstrated for reduction of lead emission achieved at a secondary lead smelter in California.
Another emissions reductions challenge is dioxins/furans (D/F). Emission limits for D/F have been reduced from 125 ng/dscm Total and 2.3 ng/dscm TEQ (corrected to 7% O2) to 25 and 0.6 ng/dscm, respectively. These emission limits are too low to be met with carbon injection. An add-on control package of re-heat and carbon bed absorber is required to meet the new limits.
Solutions to these challenges exist and facilities are taking steps to meet them. Click on the link below to download the HMIWI MACT Rule paper from the 2010 International Conference of Thermal Treatment Technologies and Hazardous Waste Combustors (IT3/HWC).