2008 — Countermeasures and Suggestions for Lishui River Pollution Control in Zhangjiajie Urban Area (Part 2)
2. The Baotagang Sewage Treatment Plant and the Sanwangpo Landfill operate abnormally due to various problems, and their pollution control functions are limited. Both plants were key livelihood projects that the municipal government pledged to the provincial government. (1) Regarding the Baotagang Sewage Treatment Plant. Currently, the plant faces three major problems: first, the settlement standard for sewage treatment fees
This article has been compiled from historical materials in the "Zhangjiajie Tour Guide Network" (33519.com · City Overview section). Some administrative divisions, population, socioeconomic data, and policy information may be outdated and are for reference only; for the latest situation, please refer to official releases by the local government and scenic areas.
II. The Baotagang sewage treatment plant and the Sanwangpo landfill site are not operating very normally due to many problems, and their pollution control functions are limited. Both plants were key projects that the municipal government promised to the provincial government that year as practical matters for the people.
(1) Regarding the Baotagang sewage treatment plant.
At present, the plant faces three major problems: First, due to disputes over the settlement standards for sewage treatment fees, settlement is not timely. In March of this year, the Municipal Price Bureau, together with the Municipal Construction Bureau and the Municipal Economic Investment Company, approved a sewage treatment fee of 0.84 yuan per ton. The plant passed environmental acceptance on May 10, 2007, reaching the Grade 1B standard of the national "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants"; the sewage treated during the earlier trial operation period did not meet this standard. The plant demands that all sewage treated before reaching the standard be settled at 0.84 yuan/ton, but the Municipal Construction Bureau, as the industry regulator, does not accept this, holding that sewage treated before reaching the standard can only be settled at operating cost (including staff wages, electricity, and chemical agent costs). Due to the inconsistent standards and untimely settlement, the plant suspended operations for nearly two months on August 26. At present, the Municipal Construction Bureau has allocated 8.45 million yuan in operating funds to the plant, but the sewage treatment fees have still not been finally settled. Second, the plant's designed treatment capacity is 20,000 tons/day, but its current actual daily treatment capacity is 16,000 tons. More than 50% of the sewage intercepted from the north bank is directly discharged into the river from the outfall of the main interception pipe, causing some pollution to the waters of this section. Third, the water from the three streams—Ximen Creek, Dongmen Creek, and Hongsha Creek—enters the north bank interception main pipe carrying a relatively large amount of solid waste. Although measures have been taken to separate and remove it, it still has a great impact on the normal operation of the plant's equipment and processes and on the plant's ability to reach full production and meet discharge standards. Countermeasures:
1. The municipal government should instruct the Municipal Construction Bureau and the Municipal Economic Investment Company to negotiate with the plant to resolve the sewage treatment fee settlement issue as soon as possible, and strive for monthly or quarterly settlement in the future to prevent arrears. The finance department should strengthen supervision over the revenue and expenditure of sewage treatment fees to ensure earmarked funds are used for their designated purpose. The environmental protection department should conduct monthly monitoring to ensure that sewage treatment meets discharge standards.
2. Regarding the problem that the corresponding treatment capacity cannot meet the designed scale and that more than 50% of sewage is directly discharged, it is suggested: ① comprehensively expand capacity and upgrade quality at the plant, striving to make the daily treatment capacity basically match the volume of intercepted sewage from the north bank; ② if capacity expansion and quality upgrading cannot be carried out at present, it is suggested to adopt temporary measures by building a pipeline from the Baotagang Sewage Treatment Plant to send both treated and untreated intercepted sewage from the north bank to an appropriate location below the Hongbiyan Power Station, so as to reduce direct pollution of the reservoir waters above the Hongbiyan Power Station by intercepted sewage from the north bank.
3. Carry out remediation of the three streams: Ximen Creek, Dongmen Creek, and Hongsha Creek. As this has been mentioned above, it will not be repeated here. The remediation of the three streams can reduce the impact of solid waste on the normal operation of the plant's equipment and processes, and improve sewage treatment capacity and the rate of meeting standards.
(II) Regarding the Sanwangpo Landfill.
The plant was invested in and built by the Municipal Economic Investment Company and was handed over to the Municipal Sanitation Department for management on April 1 of this year. The plant uses sanitary landfill methods to treat domestic waste, which produces landfill leachate with complex components, and the treatment of leachate is crucial. It is understood that leachate pollution of groundwater will last at least 200 years, and treatment is extremely difficult. At present, the biggest problem of the plant is that its landfill leachate treatment only reaches the national Grade III standard and is directly discharged, causing secondary pollution to water bodies. According to the requirements of the environmental protection department, domestic waste leachate must reach the national Grade I standard before direct discharge; otherwise it must be further treated through a sewage treatment plant. According to monitoring results from the Municipal Environmental Monitoring Center Station on October 17, the chemical oxygen demand concentration at the plant's wastewater discharge outlet was 378 mg/L, exceeding the standard by 2.8 times; the ammonia nitrogen concentration was 78.4 mg/L, exceeding the standard by 2.1 times. In addition, the plant's sewage treatment regulating tank has a small capacity (the original designed capacity was 30,000 cubic meters, but only 5,000 cubic meters was built), resulting in wastewater being directly discharged without any treatment. The waste interception dam has not been sealed; in severe weather such as rainstorms, scattered waste will rush out from the gap, seriously polluting the surrounding environment. The road for transporting waste into the site is too short, making it inconvenient to load and unload waste into the landfill operation point. Countermeasures:
1. Regarding the problem that the plant's landfill leachate treatment only reaches the national Grade III standard and is directly discharged, there are three possible solutions: ① lay a pipeline network to connect to the future Yangjiaxi Sewage Treatment Plant for further treatment (about 12 million yuan required); ② update, expand, and upgrade the current sewage treatment equipment and processes, striving to reach the national Grade I standard (about more than 5 million yuan required); ③ purchase 2–3 tanker trucks of 10–15 tons to transport the treated sewage that only reaches Grade III standard to the Baotagang or Yangjiaxi Sewage Treatment Plant for further treatment (about 1.5 million yuan required).
2. The municipal government should instruct the Municipal Economic Investment Company to complete follow-up work such as the renovation and capacity expansion of the regulating tank, sealing the reserved opening of the waste dam, and extending the road for transporting waste into the site, so as to ensure the normal operation of the plant.