The DEP manages the city’s water supply, including various other counties throughout New York State through a complex network of reservoirs, lakes, pipes, tunnels and aqueducts. This agency also manages the city's combined sewer system, which carries both storm water runoff and sanitary waste. The DEP carries out federal Clean Water Act rules and regulations, handles hazardous materials emergencies and toxic site remediation, oversees asbestos monitoring and removal, enforces the city's air and noise codes, bills and collects on city water and sewer accounts, and manages citywide water conservation programs.