ECO-COPS are sniffing the air, testing the waters and citing the stinkers. In suburban Nanhui area, Zhang Qian joins the pollution patrol and takes a deep breath.

At a lakeside in suburban Nanhui area, Zhang Lei collects water in a stainless steel bucket, then pours it into colorless plastic bottles.

Environmental authorities in Nanhui area dealt with illegal industrial discharge. [Nhhb.gov.cn]

He holds one of the bottles up to the sunlight, notes the light green color and records it in his notebook.

"The green water is relatively clean, but a bit eutrophic (rich in plant nutrients). It may be caused by the hot weather, but we won't know for sure until we get the laboratory results," says Zhang, vice director of the Inspection Section of Nanhui Environment Inspection Detachment in Pudong New Area.

After taking the water sample, Zhang and another inspector drive to a chemical plant to measure noise levels and collect water to check for pollutants.

Every day on average they inspect seven or eight spots.

Shanghai's environmental inspection teams play an important role in monitoring the environment condition, responding to complaints and urging polluting enterprises to clean up. They don't have the final say, however, and cannot order an enterprise closed.

Each district has a team monitoring construction sites, factories and plants, restaurants, farms, residential areas and other places.

Before construction begins on any enterprise, restaurant, residential complex or other major structure, an environmental impact statement is required. Builders must first show that their projects satisfies environmental regulations.

Throughout construction, inspectors monitor dirt and dust pollution, noise and solid waste.

Supervision continues after construction is completed, to check on air and water pollution, as well as noise and solid waste. Nothing is supposed to be discharged without proper treatment.

Citations can be issued and the recipient is required to respond formally in two months.

Inspectors spot check chemical, dye, paper, electroplate and other factories and respond to neighbors' complaints.

In hot weather, decay and fermentation occur faster, so inspectors check more often in summer.