Whatever company has the contract with the city to tow vehicles from accidents has the contractual obligation to sweep any glass. Any complaints should be directed to the Police Department who has responsibility to award and monitor the contract.
In regard to any public safety or maintenance issue on Division St, although that particular section is actually a state highway, the division of responsibility between the cities for all activities is as follows: Derby is responsible for the "hills" and Ansonia is responsible for the "flats". This applies to plowing, paving and response to accidents among many other public responsibilities. The referenced section of Division St is in the "flats" and is therefore Ansonia's responsibility. Ansonia is also responsible for all traffic signals and signage that do not belong to the state.