Petroleum Substance Discharge Standards for Industrial Wastewater
Regarding the discharge standards for petroleum substances in industrial wastewater, the following is a detailed interpretation of the relevant regulations.
I. General Overview
The discharge standards for petroleum substances in industrial wastewater are primarily based on the "Integrated Wastewater Discharge Standard" (GB8978-1996) as well as industry-specific discharge standards. These standards set different emission limits depending on the discharge destination of the wastewater, the environmental function of the receiving water body, and industry characteristics.
II. Specific Discharge Standards
a. Integrated Discharge Standard:
According to the "Integrated Wastewater Discharge Standard" (GB8978-1996), petroleum substances are classified as second-category pollutants. For enterprises established after January 1, 1998, the maximum allowable discharge concentration for petroleum substances is 5 mg/L when discharging into Class III water bodies (excluding designated protection zones and swimming areas) as per GB3838 and Class II sea areas as per GB3097; it is 10 mg/L when discharging into Class IV and V water bodies as per GB3838 and Class III sea areas as per GB3097; and the tertiary standard of 20 mg/L applies when discharging into urban drainage systems equipped with secondary sewage treatment plants.
b. Industry-Specific Discharge Standards:
Specific industries, such as offshore petroleum development, must comply with the "Standard for Discharge of Oily Wastewater from Offshore Petroleum Development Industry" (GB4914-2008). For produced water treated for reinjection, it must meet the water quality requirements of the injection zone; for direct discharge, the discharge limit for petroleum substances is 5 mg/L for sea areas requiring Class I water quality and 15 mg/L for Class II sea areas.
Urban sewage treatment plants must follow the "Pollutant Discharge Standards for Urban Sewage Treatment Plants" (GB18918-2002). Based on the treatment process and the environmental function of the receiving surface water body, the discharge limits for petroleum substances are divided into Level A standards (1 mg/L), Level B standards (3 mg/L), Secondary standards (5 mg/L), and Tertiary standards (15 mg/L).
c. Discharge Standards for Special Areas:
Some specific regions, such as Beijing, may have more stringent discharge standards due to environmental protection needs. When discharging wastewater in these areas, local specific regulations should be referred to and followed.
III. Considerations in Practical Application
a. Determine Discharge Destination and Receiving Water Body: Enterprises and individuals should first determine the discharge destination of the industrial wastewater and the environmental function of the receiving water body before discharge, in order to refer to the corresponding discharge standards.
b. Apply the Most Stringent Standard: In cases where multiple discharge standards exist, the most stringent standard must be followed to ensure the environment and public health are protected to the greatest extent possible.
c. Regular Monitoring and Reporting: Enterprises should regularly monitor wastewater to ensure all indicators comply with the standards and report the monitoring results to the environmental protection authorities as required.
d. Stay Informed of Regulatory Updates: As discharge standards may be adjusted over time and by region, enterprises should pay close attention to updates in relevant regulations to ensure continuous compliance with the latest legal requirements.
In summary, the strict implementation of discharge standards for petroleum substances in industrial wastewater is crucial for protecting the environment and water resources. Enterprises and individuals should fully understand and comply with the relevant standards, take effective measures to reduce the petroleum substance content in wastewater, and contribute to sustainable development.
