The acceptance monitoring of wastewater from pollution sources should be conducted under stable production conditions, with the production load reaching more than 75% of the designed production capacity. If the national or local discharge standards have specific provisions regarding the production load, those provisions shall be followed. If the overall production condition fails to meet the specified requirements, the monitoring can be carried out by adjusting the production conditions in parts according to the process and production facilities of the pollution source. For those that truly cannot be adjusted to meet the specified production conditions, with the consent of the environmental protection administrative department, the monitoring can be conducted under the condition of stable operation of the production facilities, and the monitoring results should explain this. During the monitoring period, there should be a dedicated person responsible for supervising the production conditions, and the production time and production load parameters during the monitoring period should be recorded. The production equipment and treatment facilities of the pollution source should all be in normal operating conditions. The frequency of sampling for the acceptance monitoring of pollution sources shall be determined according to the following principles:
1. The monitoring frequency should reflect the actual pollution discharge situation and the treatment effect of environmental protection treatment facilities, and should minimize the workload.
2. For emission sources with stable production and regular pollutant discharge, the sampling period should be the production cycle, and the sampling should not be less than 2 cycles. The number of samplings within each sampling cycle should generally be 3 to 5 times, but should not be less than 3 times.
3. For construction projects with sewage treatment facilities that are operating normally or have regulating ponds, if the sewage is stable, instantaneous samples can be taken, but no less than 3 times. The sampling frequency for testing the treatment efficiency of sewage treatment facilities can be appropriately reduced.
4. For non-stable emission sources and large-scale key emission sources, an intensified monitoring method must be adopted.