Environmental inspectors discover accumulated sewage in China's Anhui province

In June 2022, the Anhui Province environmental inspectors visited Huaibei and found that the food industrial park in the Xiangshan Economic Development Zone hadn't built a centralized sewage treatment facility as they previously claimed, which resulted in frequent sewage overflow into the surrounding water bodies and the environment.

To give you a context, Xiangshan Economic Development Zone built a food industrial park several years ago. The EDZ at that time didn't have a centralized sewage treatment facility, and it relied on the urban Dinglou Sewage Treatment Plant. In the beginning, everything seemed normal. After all, the "Water Pollution Prevention and Control Action Plan" stated that the EDZ would build its centralized sewage treatment facility by the end of 2017, and until then the EDZ could use Dinglou Sewage Treatment Plant.

Soon after the EDZ had been established, large amounts of high-concentration industrial sewage were discharged. Since 2013, the park had added more than 30 wading projects, increasing the average daily sewage discharge by more than 3,800 tons, which caused Dinglou Sewage Treatment Plant to be overwhelmed, and the discharged wastewater exceeded the standard many times.

Despite many complaints from the Dinglou STP management, the EDZ didn't react, claiming that the construction of the centralized sewage treatment plant had been already in process. However, it was only in September 2020 that the construction of the sewage treatment plant in the EDZ food industrial park was even considered! What makes the situation even worse, the construction of its centralized sewage treatment plant is still lagging far behind its expected time, and it's still in the phase of project land approval in 2022!

As a result, Dinglou City Domestic Sewage Treatment Plant and Information Industry Park PCB Industrial Sewage Treatment Plant tacitly stopped receiving sewage from the EDZ's food industrial park. The environmental protection inspectors visited the facility and witnessed a strange scene: the sewage in the park had nowhere to go, and about 20,000 tons of sewage accumulated in the park's pipeline network overflowed into the surrounding water bodies and the environment.

Sewage overflows everywhere in the industrial park

Failed water pollution prevention and control wasn't the only surprise for the EP inspectors. They also discovered that the treatment of black and odorous water was mismanaged. 

The second round of visits from environmental protection inspectors in 2021 discovered various complications with black and odorous water in the Fengxiang and Xiangxi ditch of the food industrial park. EDZ took several measures to put the situation under the control, such as water purification, source control, and sewage interception, but the problem wasn't solved. What's more, a large amount of sewage was continuously accumulated in the sewage pipe network of the park, overflowing everywhere, and it was discharged into the river ditches on rainy days and during flood seasons, causing severe water pollution.

In February 2022, an unannounced inspection found that the Fengxiang ditch is again composed of black and odorous water. After sampling and monitoring, the chemical oxygen demand was 372 mg/L and the ammonia nitrogen was 25 mg/L, which were 8.3 times and 24 times higher than the surface water Class III standard, respectively. On June 10 and 11, the on-site inspection found that a large amount of sewage in the sewage pipe network of the park had been overflowing from sewage wells to the rainwater pipe network, and was discharged into the water bodies around the park.

February 2022, Fengxiang ditch black and odorous water

The sewage in the sewage pipe network overflowed into the rainwater well

From 2021 to now, the number of days in which wastewater in the park exceeded the management standard has accounted for 76%, of which the chemical oxygen demand was as high as 11,424 mg/L, and the ammonia nitrogen 389 mg/L, exceeding the management standard by 21.8 times and 7.6 times respectively.

Five companies that belong to the EDZ's food industrial park were randomly checked on the spot, and 4 of them had the problem of abnormal operation of pollution control facilities or excessive discharge of wastewater.

The pollution control facilities of Meierxian food industrial park were not operating normally, and the chemical oxygen demand of the discharged wastewater was 1840 mg/L, which was 2.68 times higher than the nanotube standard.

The chemical oxygen demand of the wastewater discharged by Fubang Biotechnology was 1060 mg/L, and the ammonia nitrogen 102 mg/L, which are 1.12 times and 1.26 times higher than the nanotube standard respectively.

The pollution control facility of Shengminuo Biotechnology was shut down without authorization, and the ammonia nitrogen in the discharged wastewater was 87 mg/L, which was 0.93 times higher than the nanotube standard.

The total phosphorus in the wastewater discharged by Xianmanduo food industrial park was 10.8 mg/L, which is 0.35 times higher than the nanotube standard.

The water pollution control facility of Shengminuo Biotechnology

So what or who causes all these problems in EDZ's industrial parks?

According to relevant survey statistics, there are currently nearly 2,500 industrial parks in China that have established special facilities for water pollution. Nevertheless, the problem of water pollution in industrial parks still exists. Here are some of the reasons:

01

Industrial park planning and management lack control

Local governments often focus on local GDP and profit, so they prioritize investment projects and increase the number of companies allowed in the industrial parks. Many companies that join the parks don't have the necessary experience in water pollution treatment but are still allowed to join the park. 

In other words, local governments sacrifice environmental protection for profit, so there are no strict requirements for companies who want to move into industrial parks. Furthermore, very often the centralized sewage treatment system of the industrial park is not in place or doesn't run smoothly, because the investment project didn't take environmental issues into consideration, which in turn seriously affects water pollution.

02

The centralized sewage treatment system isn't adapted to the heterogeneous industrial sewage discharge 

The structure of industrial sewage can be very complex because the water quality components fluctuate greatly, and the sewage discharged by different companies is also quite heterogeneous. Therefore, the sewage discharged by various companies needs to be classified based on quality to ensure the normal operation of the centralized sewage treatment system.

03

Poor management leads to low efficiency of sewage treatment

Many industrial parks face issues at the management level. Management measures are often too flexible, e.g. most industrial parks allow companies to manage the pretreatment of wastewater by themselves. The flexible management structure often leads to conflicts between management departments who put blame on each other and don't want to be held accountable when things go astray, resulting in poor management efficiency.

04

The centralized sewage treatment plant and the urban sewage treatment plant in combination lead to unstable water quality

In some situations, to save money and land resources, the central sewage treatment plant and the local urban sewage treatment plant can be merged. In this case, the urban SWP accepts both urban sewage and industrial wastewater. The incomplete separation of rain and sewage in general urban areas can cause issues in sewage treatment, such as fluctuating influent water volume, low concentration, and insufficient carbon source in the sewage, all of which negatively affect the normal operation of the sewage treatment plant.

The Xiangshan Economic Development Zone in Anhui province case signals an important paradigm shift related to illegal environmental practices and environmental values and awareness in China, as national funding is diverted to support local environmental efforts in China's third-tier cities and punish any illegal practices.

Source: Anhui Ecological Environment: About 20,000 tons of sewage accumulated in the pipeline network of an industrial park, overflowing everywhere! Water supply and drainage: Status and development of sewage treatment in industrial parks; Engineering technology and management: Research on problems and countermeasures of water pollution prevention and control in industrial parks under the current situation.