To tighten or loosen water quality effluent standards for pollutants?

Excerpt

Water quality control for rivers, lakes, seas, and groundwater in Japan is enforced by the Water Pollution Control Law, which sets the Environmental Quality Standard (EQS) for targeted water quality to preserve human health and the living environment. For 28 toxic substances including mercury and PCBs, uniform EQS values are applied all over the country. These standard values are at the same levels as those for tap water. On the contrary, eight specific items including BOD and COD have different standard values depending on utilization objectives of each water body. Fulfillment of EQS is evaluated by environmental monitoring at 5,400 points (216,000 samples) in rivers, lakes, and sea areas, and at about 10,000 points in groundwater. …