In some underdeveloped areas in the upper and middle reaches of the Yellow River, some sewage treatment plants have been reduced to septic tanks
A sewage aeration tank is placed in a steel shed at a sewage treatment plant in Gander county, east China's Jiangsu province, Sept. 11, 2020.
Built a sewage treatment plant, there are still a lot of sewage straight discharge, eventually into the Yellow River; Due to high operating costs, some sewage treatment stations have no choice but to "sleep" or even "become" septic tanks.
Xinhua Daily Telegraph reporter recently visited a number of underdeveloped areas along the upper and middle reaches of the Yellow River and found that due to poor infrastructure, poor equipment operation and high daily operation costs, many areas have "built sewage treatment plants and sewage treatment is still difficult."
There are treatment plants but still direct discharge of sewage, pollution control in the upper and middle reaches of the Yellow River is still a problem
Multi-party investment in the construction of sewage treatment plants, due to insufficient treatment capacity, low efficiency, limited coverage, sewage is still difficult to "full collection, full treatment." Some residents' domestic sewage can only be discharged directly and eventually into the Yellow River, which is what the reporter saw when visiting the middle and upper reaches of the Yellow River basin.
In a county in the middle reaches of the Yellow River, there is a first class tributary of the Yellow River through the territory. Local environmental protection officials introduced that in recent years, due to strengthened supervision, industrial wastewater is basically discharged according to the standard, and the main pollution comes from rural domestic sewage. To this end, two small sewage treatment stations have been built in towns far away from the county seat, but the operation status is not satisfactory.
The reporter came to the bank of a township river with a small sewage treatment station and saw that many residents' domestic sewage was discharged directly into the river through pipes. When pipes are broken, sewage flows directly down the dam to the riverbed, staining the brick walls black.
A staff member of the local environmental protection department introduced that although in 2018, with the support of the municipal and county-level finance, the township built a new sewage treatment station, the construction cost of the supporting pipe network is too high, and the domestic sewage can only be collected by nearly half of the town's population, and the actual treatment capacity is only half of the design capacity.
To this end, the county construction department built 20 water storage tanks along the river bank in the local area, temporarily collecting residents' domestic sewage, and then centralized transport through the sewage collection truck to the nearby sewage treatment station. Some staff admitted, "The processing capacity of the treatment station is limited, and the equipment such as pumps often has problems, many times it is too late to pull, and the sewage from the storage tank overflows, which also causes the sewage to flow directly into the river."
Gande County, Guoluo Tibetan Autonomous Prefecture, Qinghai Province, is located in the source of three rivers, close to the source of the Yellow River. The reporter saw in the Gander County sewage treatment plant that the conventional open-air sewage aeration pool was placed in a steel shed house. Into the steel shed room, obviously feel the indoor temperature increase.
"There is no way, the temperature here is low, and the microorganisms that treat sewage are easy to freeze to death, so the aeration tank can only be installed indoors and the boiler is burned to keep warm." The person in charge of the sewage treatment plant said that the Gander County sewage treatment plant is more than 4,000 meters above sea level, and the winter temperature is low, and it must be insulated by the outer steel shed house and the internal boiler.
"The cost of burning coal for boilers alone is about 250,000 yuan a year, which is not a small expense." The person in charge said that the Qinghai-Tibet Plateau is large and sparsely populated, and the temperature difference between day and night is large, resulting in difficult sewage treatment and high construction and operation costs.
More urgent is that the total investment of more than 20 million yuan to build the Gande County sewage treatment plant, mainly to treat the county residential areas, office buildings and shops of domestic sewage. At present, the daily processing capacity is 1200 tons, which has been running at full capacity, and it is urgent to expand and improve the processing capacity.
Construction and operation costs are high and the burden is heavy, and some sewage treatment plants have been reduced to septic tanks
The reporter visited and found that the main reason why some underdeveloped areas in the middle and upper reaches of the Yellow River basin "have sewage treatment plants and are still difficult to treat sewage" is that the construction cost of the collection sewage network is high and the sewage treatment operation burden is heavy. In particular, many underdeveloped counties have just lifted themselves out of poverty, and their financial resources are limited, making it difficult to bear the construction and operation costs of "full collection and full treatment" of sewage.
In Yongjing County, Hui Autonomous Prefecture of Linxia, Gansu Province, there was no sewage treatment plant in the county more than a decade ago, and domestic sewage was treated by septic tanks and discharged directly into the Yellow River. In recent years, with the completion of sewage treatment plants and pipe networks, more than 85% of the sewage in urban areas can be collected, but it is still difficult to cover all areas such as the urban and rural junction.
"The cost of pipe network construction is about 1 million yuan per kilometer, especially in the old city, there are pipe network aging, rain and pollution mixed flow problems, the cost of laying a new pipe network is very high." Yongjing County housing Bureau cadres Wang Xiaoming introduced.
With the acceleration of urbanization, the relocation of poverty alleviation in inhospitable areas, the increase of county and urban residents, the increase of sewage discharge, sewage treatment plants must also be expanded. Although local financial resources are limited, under the huge ecological and environmental pressure, "debt" expansion of sewage treatment plants has become a common choice in many underdeveloped areas.
Gao Chuncheng, director of Xinmin sewage treatment plant in Linxian County, Luliang City, Shanxi Province, introduced that due to the increase in the population living in cities and towns, the original equipment treatment capacity lags behind, so the expansion and transformation of the existing sewage treatment plant was completed in 2020, "although the transformation funds were seriously insufficient at that time, it can only start first, and then find a way to spend money later."
At the same time, the less developed areas in the middle and upper reaches of the Yellow River basin due to relatively low population density, low sewage concentration, coupled with low temperature and other factors, the cost of sewage treatment is much higher than that in the developed areas in the east. Some sewage treatment plants are kept running and require a daily infusion of glucose.
Li Shukun, director of Yanguoxia Town sewage treatment plant in Yongjing County, said that the town's population is small, and the water from the sewage plant mainly depends on residents' domestic water. The low COD concentration of the influent leads to insufficient carbon source when the microorganisms treat the sewage, and can only ensure that the microorganisms are not "starved to death" by adding glucose, and "three or four tons of glucose are added every month, which directly increases the treatment cost."
The reporter learned that at present, a total of 14 county sewage treatment plants in Qinghai Province are in high-altitude areas, and there are widespread problems such as low sewage concentration, low treatment efficiency, low collection rate, and insufficient rain and pollution diversion. Coupled with the low winter temperature in the Sanjiangyuan area, the sewage treatment process has brought great challenges, and it is generally necessary to warm the shed and supply heating, and some sewage treatment tons of water cost up to 4 yuan per ton.
In Xinyi Town, Lishi District, Luliang City, Shanxi Province, the completed sewage treatment plant had to be shut down because it could not afford the subsequent operation costs. Wang Sanniu, deputy mayor of Xinyi Town, said that after the completion of the sewage treatment plant, governments at all levels did not follow up to ensure the operation of funds, and the town government alone was difficult to bear the cost.
"Some sewage treatment plants were built early, the treated sewage is difficult to meet the existing discharge standards, there is no money to upgrade the equipment, and now it can only be used as septic tanks." Wang Sanniu admitted.
Sewage treatment can not "regardless of the construction of the operation"
The construction has superior capital investment, the operation depends on the level of financial investment guarantee, high operating costs of sewage treatment plants, so that many sewage treatment plants "embarrassed burden". Gander County, Qinghai Province, which got rid of poverty in April 2020, had a fiscal revenue of 16.74 million yuan at the county level in 2019. The county pays 1.5 million yuan a year for sewage treatment, accounting for nearly one-tenth of the level's fiscal revenue in 2019.
Some grassroots interviewees appealed that many less developed areas that have just taken off their hats are in ecologically fragile areas, with high pressure on ecological and environmental protection and tight local financial operation. In view of the actual financial situation in these areas, the construction and daily operation of sewage treatment plants need national policy support.
On the one hand, the investment in the construction of the sewage treatment plant itself is 12 million to 20 million yuan, and the local supporting funds are only 2 million to 4 million yuan, which can only use local fiscal revenue and expenditure, and many times the local government can only default. It is suggested that the state reduce the proportion of funds supporting these underdeveloped and restricted areas, so as to facilitate the expansion and construction of related sewage treatment and collection projects. On the other hand, urbanization in many underdeveloped areas is still in its infancy, and many regions have not yet established charging mechanisms for tap water, garbage treatment, and domestic sewage. The operating costs of sewage treatment are completely under the pressure of local fiscal expenditures, so PPP model cannot be adopted for construction. It is urgent to change the situation of "managing construction regardless of operation" of national special funds, and give certain operating fund subsidies to alleviate local financial pressure.
Improving the mechanism of timely discovery, timely collection and timely treatment of direct sewage discharge is also an urgent need to fill the shortcomings. Gao Guoping, deputy director of the Linxian Branch of the Ecological Environment Bureau of Luliang City, Shanxi Province, and other cadres suggested that a comprehensive investigation of sewage outlets, the installation of video surveillance equipment in key areas, and the use of drone shooting and other means of real-time monitoring, while insisting on the combination of scientific and technological means and artificial means, increase artificial inspection efforts to ensure that domestic sewage is treated accordingly, and eliminate direct discharge and stolen discharge.
"For the towns without industrial enterprises, close to the urban pipe network, the production of rural domestic sewage is limited, it is recommended to take the decentralized construction of storage tanks, through centralized transport treatment, reduce the cost of treatment." Suggested by Wang Chaobo, deputy director of the Ecological Environment Bureau of Tianshui City, Gansu Province.
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