if the catering business area reaches more than 51 square meters, a pollutant discharge permit is required.

Drainage permit is a supervision and management certificate issued by enterprises, institutions and individual industrial and commercial households engaged in catering, industry, construction, medical treatment and other activities to discharge sewage into urban drainage facilities. Catering enterprises are key drainage households. According to the law, drainage households that have not applied for drainage permits are not allowed to discharge sewage into urban drainage facilities, and offenders will be investigated for legal responsibility.