After three months of back and forth, state and federal regulators gave final approval today of phase 1 of Harbor Point – the construction of the Exelon Tower, Central Plaza Garage and related infrastructure.

The approval allows developer Michael Beatty to begin preparatory construction activities on the 27-acre site on the western edge of Fells Point.

But Beatty Development must still submit an air monitoring plan to the Environmental Protection Agency (EPA) and Maryland Department of the Environment (EPA) before the five-foot-thick protective cap can be breached.

The cap entombs about 2 million tons of soil and debris contaminated with hexavalent chromium, a cancer-causing byproduct of the chromium chemicals once manufactured at the site, a former Allied Chemical factory.

Air Monitoring Still Needed

Beatty’s initial air monitoring plan, which would set a baseline for hexavalent chromium in the atmosphere surrounding the site, was rejected in October.

New monitoring data must be collected before the developer can penetrate the cap to start building the foundation of the Exelon Tower. Beatty has not yet submitted a final air monitoring plan.

“We anticipate that an air monitoring plan could be approved by early January,” MDE spokesman Jay Apperson said this afternoon. Construction could begin after 15 days of data collection is complete and analyzed, Apperson said.

Beatty is under heavy time pressure to start work on the regional office tower of energy giant Exelon, which is scheduled to open in mid-2015.

In September, the Baltimore City Council approved $107 million in TIF tax financing  to build roads and other infrastructure at the site, but the city has delayed issuing the first tranche of TIF bonds until EPA-MDE approval was granted.

Under a 1989 consent decree between the EPA, MDE and current property owner, Honeywell International, construction over the capped area should not stir up dust or release contaminants into harbor waters that increase dangers to human health or the environment.

Today’s approval marks a major step forward for the planned $1 billion office, apartment and retail complex – the largest ever attempted in Baltimore – that has been wracked by controversies over tax breaks and environmental concerns for the last six months.