Hanover and state environmental and public health officials will gather in the town together publicly for the first time Nov. 14 to address the impact and resolution of the contaminated 240-acre National Fireworks site.
Six decades of manufacturing civilian fireworks and later US military munitions for four wars have resulted in enough mercury, lead, and other chemicals in the soil, wetlands, and adjoining waterways to earn the parcel one of the highest hazardous designations in the state.
Still, said Hanover Town Manager Troy Clarkson, next Wednesday’s communal meeting will also be used as a vehicle to clear up misinformation that the affected portion of the property — in use from 1907 to 1970 — poses a health or other risk.
In a mailing to 6,000 homes and businesses preceding the meeting, Clarkson said the site has not had any effect on property values, the town’s water supply, or any discernible link to clusters of disease, a key concern for Hanover residents.
“We have produced definitive information on the health impacts at this point, based on the contaminants, that show no link to cancer rates,’’ he said. “They are not elevated in Hanover at all.”
In a letter dated Dec. 19, 2011, the state Department of Public Health determined that cancer statistics in the town did not appear unusual, Clarkson said.
The site, which also borders Pembroke and Hanson, is bounded by Winter, King, and First streets, the Drinkwater River wetland, and Factory Pond, according to the mailing. An industrial park operates in the northern and eastern portions of the property.
A legendary producer of pyrotechnics from firecrackers to cherry bombs, National Fireworks was a major employer in Hanover in the early 20th century. At the meeting next week, state officials will also update residents on progress to get former owners and users of the property to pay for its cleanup. Those include the Massachusetts Institute of Technology and the Department of Defense.
“This meeting will be like one-stop shopping for citizens,’’ Clarkson said. “It’s important that we are speaking with one voice.”
State Department of Environmental Protection spokesman Joe Ferson said agency officials are attending the meeting at the invitation of Hanover selectmen. The department has overseen all investigations and remedial activities at the site since 1995.
“We will clarify any issues they have and also provide answers about the cleanup at the site,’’ Ferson said. “We are happy to provide those answers to the extent public information is available.”
The agency had set a June deadline to reach agreement with the parties responsible for the pollution or seek Superfund status, a designation given to the nation’s most contaminated sites.
Under that scenario, the US Environmental Protection Agency would lead the effort to clean up the site. But Clarkson and selectmen chairman John Barry were able to persuade the state to keep the cleanup local so that the town can remain involved.
Selectmen, who want to use some of the remediated land for economic development, have also authorized Barry to set up a committee to look at future uses for the land when the cleanup is complete, Clarkson said.
State officials have said that munitions and other explosives were often exploded in Factory Pond, which accounts for its levels of lead azeide, often used as a detonator. Such materials don’t go away easily, especially after leaching underground, they said.
The National Fireworks property is designated Tier 1A for containing the most serious level of contamination, according to state standards. The state has already completed three cleanup phases, including removing drums of chemicals. Under Phase 4, ecological hazards would be excavated from the sediment or capped, officials said.
On the table are six options, ranging from a temporary measure to remove some silt and soil for about $5 million to a $158 million plan to remove all hazardous materials. The median cost is $27.8 million.
The state is negotiating with the Fireworks Site Joint Defense Group, which includes National Coating Inc., MIT, and the Department of Defense. Tronox, once known as Kerr-McGee Chemical Co., settled with the federal government in 2009 and then went bankrupt. Still, $950,000 of that settlement will go toward remediation, town and state officials said.
Clarkson said he is eager for the meeting, which he considers a landmark development in moving forward. “When you have a site like this, you have to take a holistic approach,’’ he said.
What’s equally important, though, is being sure that residents feel they are involved, he said. “The selectmen set a goal for me to improve communication with the public, and that is what I am trying to do.”
The meeting will be held at Hanover High School at 7 p.m.