CohoesA not-for-profit Boston developer is eyeing a $10 million apartment project off Interstate-787 in Cohoes.Plans by Community Builders, which five years ago redeveloped former mill worker housing in Cohoes, call for 39 apartment units on a vacant former industrial property on Saratoga Street just north of the offices of Mohawk Paper.The developer also expects to spend about $1.5 million to investigate and clean pollution from the 1.7-acre parcel, including toxic heavy metals such as arsenic, cadmium, chromium, copper, lead, mercury and barium.