Wastewater monitoring and evaluation of compliance with Maximum Allowable Values (MAV) in primary collectors of the drainage area of a wastewater treatment plant

Abstract

The physicochemical monitoring and evaluation of wastewater in the critical drainage areas corresponding to the Puente Piedra WWTP, Lima, was carried out. For this purpose, the geographical position, the number of Non-Domestic Users (NDUs) and the identification of NDUs with high wastewater discharges were considered. In the critical areas, wastewater monitoring points were established, corresponding to sewage inlets, where quality was evaluated through compliance with the Maximum Allowable Values (MAV) of D.S. 021-2009- VIVIENDA. The monitoring plan covered a control period of 8 hours with spot monitoring carried out every 2 hours. At monitoring points BZ-70651 and BZ-59124, excess AMVs were found for pH (>14), BOD5, COD, TSS, oils and grease due to the presence of textile and paper manufacturing industries; at point BZ-212339 there was an excess of BOD5, COD, TSS, oils and grease, and sedimentable solids as a result of organic material released by businesses, restaurants and domestic users; at point BZ-46847 there was no excess of AMVs; and at point BZ-212344 BOD5 was exceeded due to discharges from businesses, domestic users and industries. It is recommended to extend the application of the regulations, considering the biological analysis parameters, improve UND control in the drainage area, establish continuous monitoring stations and replicate the described procedure to other areas.