Tight limits were set on disposal into the rivers at only 1.5 degrees above their ambientlevel.
污水排放入河有严格的标准要求，其污染度只能是周围环境的1.5度。
2
This demands to monitor and simulate what is ambientlevel of pollutants in distinct time and place.
这就需要监测和模拟一系列污染物在不同时间和不同空间的环境水平。
3
Enforcement was possible only when a discharge reduced the quality of the receiving water below the specified ambientlevel, or to prevent an imminent health hazard.