The quality of influent is presented in Table 7.6. Quality of Influent. As results, there are some comments as below:
In general, concentrations of the contaminants in the influent are relatively low.
The influent in the combined and partially separated sewers: some criteria in the many stations did not pass Column B of Standards (QC 14 and QCVN 40) as: COD in Bac Ninh. Da Nang and Soc Trang WWTPs; TSS - Phu My Hung
The main reason for this is that the domestic wastewater is preliminary treated in septic tanks and then collected into sewer system together with storm water.
In general, the quality of effluent met requirements. even where the requirements specified in column A (Binh Duong);
The percentage of tested samples that passed the relevant standard are shown in Table 7.8 and found that almost of utilities as of 100% excluding Quang Binh (96%). HCMC (83%).
Figure 7.4: Percentage of tested samples that passed the relevant standard by DoNRE
Figure 7.5: Percentage of tested samples that passed the relevant standard by Utility
7.5.3. Quality control
Table 7.8 summaries the quality control of the Utilities. As results, it presents some comments as below:
Quality management system according to ISO 9001: Only 4/13 complied with as including Hanoi. Dak Lak. HCM City and Binh Duong. The remaining utilities (9/13) should consider to develop a quality management system.
The number of complaints about wastewater treatment that received in the year: all utilities excluding Soc Trang reported that they did not receive any complaints. However, the data seem to be considered as reference as the people did not send written complaints as practices. In fact, the media has reflected people's reactions relating to the odors generated from wastewater treatment stations using covered anaerobic lagoon in Da Nang and the remedial measures has been taken.
Staff training: Only 2/13 utilities including Da Nang and Soc Trang with training costs for staff. The utilities needs to pay much attention to the staff training on regular basis as in fact the staffs in WWTPs always changed by leaving of the skilled staffs.