During the acceptance monitoring process, the scientific verification of wastewater discharge constitutes a critical link. In practical operations, verification is typically conducted based on the readings of an enterprise’s wastewater flowmeter; however, special cases do exist. This paper analyzes the acceptance monitoring of wastewater discharge volume under several such special scenarios.
1.In the acceptance monitoring of wastewater treatment facilities, some enterprises resort to hidden pipes for unauthorized discharge or leakage to ensure their wastewater meets discharge standards. For industries with high-concentration wastewater, a dilution ratio is permitted prior to pretreatment. Nevertheless, certain enterprises arbitrarily increase the dilution ratio to reduce pollutant concentration or install hidden tap water pipes downstream of treatment facilities to lower both discharge concentration and volume—all in an attempt to meet standards while cutting treatment costs. In such cases, monitoring personnel must not only conduct routine discharge monitoring but also carefully verify the water volume of the treatment facilities by comparing influent and effluent volumes. This comparison facilitates the inspection of whether the facilities are operating to treat wastewater in a timely and qualified manner.
2.Defects in pollution control facilities may result in effluent failing to meet discharge standards under normal operation. To address this, some enterprises pre-treat stored wastewater during the period of online water quality monitoring to fabricate compliant results, thereby falsely demonstrating the facilities’ qualification and treatment capacity. Such practices are unacceptable for acceptance. When encountering this situation, monitoring personnel should conduct detailed on-site investigations to understand the wastewater treatment process, particularly the hydraulic retention time (HRT) of each treatment stage during facility operation. This allows verification of whether the actual discharge volume and cycle align with the expected operational parameters.
Installing water quality monitors at wastewater discharge outlets ensures compliant discharge and safe water usage. Monitoring personnel must comprehensively verify an enterprise’s wastewater discharge volume and cycle, and accurately record influent and effluent volumes. This enables precise assessment of total discharge volume during concentration evaluation, ensuring both the discharge concentration and total load remain within the qualified range.
