Pulled out my records from this year's legislative session on this:
This tax is the "Chesapeake Bay Watershed Restoration Fund" from HB555/SB320 from the 2004 Maryland Legislative Session. This fund is created within the Maryland Department of the Environment. The environmental surcharge is imposed on users of wastewater facilities. The residential charge is $2.50 per month (which is also the base for the septic system $30/year.) Non-Residential (ie. Business/Commercial users) will be surcharged based on the wastewater they generate at the rate of $2.50 per month for every 250 gallons, with a cap of 8000 EDU's. (Gee - a $20,000 dollar cap! THANKS!) It also establishes a Watershed Restoration Fund Advisory Committee, and specifies committee's terms/composition/duties...
Look for increased prices at restaurants, car washes, printers, and pretty much anywhere with more than 1 or 2 employees, which will quickly reach the EDU Cap.
But ultimately, as I said, the money generated will go to upgrade Baltimore's failing wastewater treatment facilities that are basically "taking a dump" in the Bay.