MARBLEHEAD-The Conservation Commission has given Woodard and Curran the authority to clean up the contaminated soil of the former Chadwick Lead Mills site on the Salem line – and that clean-up can proceed whether real estate developer KSS Realty Partners gets permission to build 45 condominiums on the site or not.However, W&C can’t do any work until the owner of the property, National Lead, gets permission from the town to clean up an area of land the town owns at the site – and negotiations between NL and the town are still on-going.The commission held the last portion of its hearing on the clean-up Thursday evening and approved a four-page, 29-paragraph order of conditions for the clean-up by a 3-0 vote. The five-year order states that the clean-up will be overseen by an environmental scientist working for the town and paid for by W&C.Daniel Garson, W&C vice president, said the clean-up will include the removal of more than 1,000 cubic yards of material from the contaminated beach area and replacement of that material with clean fill and plants.As for the town-owned land, Garson said, “We expect NL and the town to reach agreement and we will then seek an amended order of conditions for that small added area of Marblehead land.”Commission Chairman Walter Haug reminded him that the cleanup must begin in the fall and the company has said it would like to start this October.Ted Tobin of KSS submitted plans for the company’s proposed landscaping in the area. “KSS wants to make sure that W&C doesn’t contradict what we have planned,” he said. “For instance, we have a set of stairs going to the beach.”Haug accepted the plans but pointed out that the stairs appear to cross the town-owned land, which will be added to the order of conditions when the town-NL negotiations conclude.