Clean Water

Abstract

Thanks to the sound, and high-quality water supply system, the Cabinda Water Supply Project in Angola has not only provided local residents with safe and clean drinking water for effectively improving people’s livelihood, but also improved local environment and delivered more benefits to communities, by means of construction and operation of sustainable infrastructure and social services as well, resulting in the accelerated progress of realizing the SDG6: Ensure access to water and sanitation for all.

3.1 Cabinda Water Supply Project in Angola

Thanks to the sound, and high-quality water supply system, the Cabinda Water Supply Project in Angola has not only provided local residents with safe and clean drinking water for effectively improving people’s livelihood, but also improved local environment and delivered more benefits to communities, by means of construction and operation of sustainable infrastructure and social services as well, resulting in the accelerated progress of realizing the SDG6: Ensure access to water and sanitation for all. After the project is completed, the water supply system will be able to cover 95% of the populated areas of Cabinda. In addition, the project will deliver water to seven water plants in Cabinda City and neighboring cities (regions) to tame the challenge of insufficient water supply. At the same time, it will provide clean and safe drinking water to nearly 110,000 households (over 600,000 people in total) in the city through nine looped water supply networks, secondary pipeline networks, household pipeline networks and public water supply facilities. According to the Sustainable Development Goals Report 2020, Angola is securing increasingly positive progress on the way to meeting SDG6, which is largely attributed to this water supply project.

3.1.1 Background

Cabinda Province is an enclave in northernmost Angola, covering an area of 7,270 km², with the Republic of the Congo to the north, the Democratic Republic of the Congo to the east, and the Atlantic Ocean to the west.¹ As of mid-2019, the province was home to approximately 820,000 residents with around 790,000 living in the urban area,² most of whom reside in Cabinda City, capital city of the province. Cabinda Province is also the second largest city following Luanda, capital city of Angola and one of the political and economic hubs of the country.

The Chiloango River and other two main rivers running through the Cabinda Province are the major water sources of agricultural and industrial production and domestic use. As the industrialization has gathered speed in recent years, environmental pollution has been getting worse and the water quality of rivers and streams which play a significant role in water supply for urban residents is suffering ongoing degradation, severely undermining the safety of domestic water use. Besides, the municipal infrastructure in the urban area of Cabinda including water supply facilities and urban roads is in poor condition. The low coverage rate and penetration rate of the water supply system, and the uneven distribution of water supply has led to unstable quality and availability of domestic water use for most residents. Prior to the launch of the project, about 40 to 50% of the population in the city had no access to clean water for domestic use.³ Poor hygiene conditions combined with the shortage of water resources as well have pushed up the morbidity of malaria, diarrhea and cholera in the region.⁴ Thus, it has become imperative to improve the safety, reliability, cleanness and relevant hygiene conditions of water supply, given the increasing demands for clean water resulting from an expanding urban population. Hence, the government of Angola decided to launch the Cabinda Water Supply Project to improve local people’s livelihood.

3.1.2 Project Overview

The Cabinda Water Supply Project, the most important livelihood project in Cabinda Province, is initiated and funded by the Ministry of Energy and Water of Angola and supervised by PROFIS, an engineering consulting firm. China Railway Construction Corporation Limited (CRCC) is responsible for the design, construction, and pre-stage operation and maintenance of the project, which consists of a whole set of water supply facilities including pumping stations, water purification plants, high-level reservoirs and water filtration pipelines.⁵ The project was kicked off in October 2016. Section I of the project is primarily responsible for the restoration of ETA2-THIZO, a water supply system and the construction of 7,000 m³ high-level reservoirs, 48.6 km main water supply pipelines and 18 km water distribution networks. Section II sets out to build five 5,550 m³ large concrete reservoirs, three 50 m³-370 m³ water towers, one office building, 24 km main water distribution pipelines, nine looped networks across the province with a total length of 64 km, 1,100 km supporting secondary pipeline networks and household pipeline networks, and 219 public water supply facilities.

By October 2020, Section I had been completed successfully. As to Section II, reservoirs, water towers, the office building, main water distribution pipelines, nine looped networks and 200 km supporting secondary pipeline networks and household pipeline networks have been put in place. The construction of remaining supporting secondary pipeline networks and household pipeline networks, and household connection work are under way.

After the project is completed, the water supply system will be able to cover 95% of the populated areas of Cabinda Province. While delivering water to seven water plants in the urban area, it also provides clean and safe water for over 600,000 residents through nine looped pipeline networks, secondary pipeline networks, household pipeline networks and public water supply facilities.

The Cabinda Water Supply Project could solve the its problems troubling the production, storage and distribution of drinking water and provide user-friendly and efficient processing and supply system of drinking water that can be easily and rapidly operated and maintained at a low cost. As the project gives priority to public health, it has eliminated and reduced secondary pollution in the water supply project, improved the quality of drinking water, realized safer and cleaner drinking water supply, improved the health of local people, facilitated water fetching, and improved the living standards of local residents. It has also laid a solid foundation for the province to carry out the reform of water conservancy, planning of drinking water and urban planning, and pursue economic growth (Fig. 3.1).

Fig. 3.1

Construction of the cabinda water supply project

3.1.3 Strict Measures for Environmental Protection

At the beginning of the project, the CRCC commissioned a local environmental assessment firm to conduct an all-round investigation into the overall environmental impact of the project and protective measures needed. Then, it prepared the “Plan for Engineering Environment and Social Management” (hereinafter referred to as the Management Plan) in accordance with the standards and requirements laid down in the Basic Environmental Law (No. 5/98), Decree No. 51/04 on Environmental Impact Assessment (EIA) promulgated on July 23, 2004 and the National Environmental Management Plan (PN GA), and filed with the employer and department of environmental protection for approval and record. Afterwards, the CRCC has strictly implemented the Management Plan throughout the process under the supervision of the employer, the supervisor and the local department of environmental protection (Fig. 3.2).

Fig. 3.2

Plan for engineering environment and social management

Since the implementation of the project, the CRCC has followed relevant requirements set forth in GB/T 24,001:2016 and ISO 14,001: 2015 for environmental management systems to push forward the project by establishing a system featuring the sharing of design, construction and utilization between facilities for the management of energy conservation and environmental protection and the project construction. In so doing, the CRCC has fully disclosed its technology beforehand, exercised stringent supervision and control during the process and performed scientific assessment afterwards. The CRCC has also met the “six 100% construction site standards” used in China, namely ensuring 100% enclosure of the construction site, 100% coverage of construction materials, 100% coverage of water-based operation procedures in earth excavation, 100% coverage of tarmac and cement roads, 100% coverage of vehicle washing services and 100% coverage of airtight transportation by trucks carrying construction waste.

In order to ensure the waterproofing materials on the inner walls of the eight concrete reservoirs are harmless to the human body and meet the requirements of ecological and environmental protection, the CRCC took the initiative to communicate with the employer and supervisor and adopted Sika, a new environmentally-friendly waterproofing coating solution that can come in contact with drinking water as ratified by the French High Council for Public Health. This decision has not only ensured the quality of the construction work and realized the waterproofing requirement, but also prevented environmental pollution (Fig. 3.3).

Fig. 3.3

Application of sika, waterproofing coating

3.1.4 Solution to Surface Runoff and Rainfall Erosion

Cabinda Province, with an equatorial rainforest climate, is mainly a hilly area with a vulnerable ecological system. The rainy season begins in October and ends in next May with frequent and heavy rainfall. Hence, the province frequently struggles against surface runoff and rainfall erosion, gully erosion and other natural disasters, which have become a stubborn challenge for the local government and residents as well as an acute problem in the project construction.

All things considered, the CRCC has taken a mix of measures to effectively solve the problem. To begin with, it has prepared a general plan according to the climate and geological characteristics of the province, so that the construction work on steep road segments with deep foundation trenches can be carried out during the dry season. Furthermore, it has employed green technology and approaches to reinforce the project. To be more specific, it makes the best of waste bituminous concrete removed from paved road segments to pave those severely affected by rainfall. Next, rollers are used to compact the road, so as to protect backfilled grooves against rain-wash. In addition, the CRCC has strengthened the control of surrounding slopes. For slopes which are not part of the road, it has used ecological technology to protect these slopes after laying pipeline through boosting the vegetation coverage in a timely manner, so as to reinforce slopes and prevent runoff-induced landslides (Figs. 3.4 and 3.5).

Fig. 3.4

Use of waste bituminous concrete to protect steep road segments from runoff

Fig. 3.5

Growing plants on slopes to prevent runoff

3.1.5 Sound Environmental and Social Benefits

In the course of carrying out the Cabinda Water Supply Project, the project management staff of the CRCC has strictly abided by local laws and regulations, respected local customs, helped the local government with economic growth and worked hard on employment and people’s well-being. While ensuring the water supply project delivers its intrinsic environmental and social benefits, it has substantially improved the environment and boosted community well-being.

• (1) Environment-friendly measures

  In the course of construction, the CRCC has regulated the use of machinery, strictly avoided local residents’ rest time, imposed speed limits, prohibited honking without good cause, ensured that trucks are sufficiently covered and took measures like water-spraying to reduce dust concentration. With these measures in place, the CRCC has ensured that local residents are not disturbed by the noise of machinery and equipment and that there is no environmental pollution resulting from engineering operations. It is not only well-received among the public, but also repeatedly interviewed and promoted by the national media of Angola. High-ranking government officials like the President of Angola, the Minister of Energy and Water and the Governor of Cabinda Province paid several visits to the construction site, during which they expressed appreciation for and spoke highly of the Chinese enterprise for its attempt to protect the environment and fulfil social responsibility in the implementation of the project (Figs. 3.6 and 3.7).

  Fig. 3.6

  

  OPAIS news, Angola’s state newspaper actively reported the cabinda water supply project

  Fig. 3.7

  

  The president of Angola investigated the construction site

• (2) Creation of Jobs and Enhancement of Workers’ Vocational Skills

  While carrying out the project, the CRCC has recruited many local workers and continuously created job opportunities. The ratio of Chinese workers to Angolan workers of the project has witnessed a growth from 3:7 at the very beginning to 1:17. Since the project was kicked off, it has provided approximately 400 jobs for local residents on average every day, helping the local department of labor to create jobs for about 6,000 people. As an employer, the CRCC has fully respected all kinds of rights of its workers, created a positive working environment, paid workers generously and supported them to settle disputes with the help of the local department of labor. Thanks to well-regulated employment practices, the project has never met with any labor dispute since the launch.

  The CRCC has also worked hard to improve the skills and abilities of local workers. At present, the skills of Angolan team leaders, safety officers, mechanical operators and measurement teams are as good as Chinese employees. In order to realize the sustainable operation and management of the project, the CRCC has also concluded a deal with the water company of Cabinda to train 20 technicians for the latter, who will take charge of the routine operation of the project after it is handed over to the latte.

• (3) Establishment of Communication Channels to Serve the Local Community

  Since the pre-stage of the project, the CRCC has established ties with the local government and water firm to grasp information of local demands and provided services as best as it can, so as to enhance community well-being. During the implementation of the project, it often helps the local water firm to repair damaged water pipelines, cooperates with government departments on the removal of urban garbage, delivers water to residents living nearby free of charge and provides local employees with regular and irregular physical examination. After COVID-19 broke out, in response to the request of the Ministry of Energy and Water of Angola, the CRCC has borrowed a water tanker to the local water firm free of charge to satisfy local people’s basic needs (Figs. 3.8, 3.9 and 3.10).

  Fig. 3.8

  

  The CRCC is helping local government organs repair damaged water supply pipelines

  Fig. 3.9

  

  The CRCC delivers free water to local residents

  Fig. 3.10

  

  The CRCC provides regular physical examination for local workers

3.2 Padma (Jashaldia) Water Treatment Plant Project in Bangladesh

The Padma (Jashaldia) Water Treatment Plant Project in Bangladesh is a vital livelihood project jointly promoted by the Chinese government and the Bangladeshi government under the framework of the BRI. The project could improve the water quality of Dhaka, capital of Bangladesh, step up environmental protection, improve people’s living quality, help Bangladesh realize SDG6, and contribute to its sustainable economic and social growth.

3.2.1 Background

With a large river network, Bangladesh is known as the “land of rivers.” However, the country faces the severe shortage of water treatment facilities. Its capital city Dhaka primarily relies on groundwater for the supply of drinking water. With the depletion of groundwater and worsening pollution of water sources (arsenic levels are dangerously high) in Dhaka, it has become imperative for the Bangladeshi government to provide citizens with safe and clean drinking water, which is vital to its economy and people’s livelihood.

The Bangladesh-China-India-Myanmar (BCIM) Economic Corridor is one of the six economic corridors envisioned in the BRI planning. Bangladesh, an important party in the BCIM Economic Corridor actively participates in the cooperation under the framework of the BRI. The Padma (Jashaldia) Water Treatment Plant in Bangladesh undertaken by China CAMC Engineering Co., Ltd. (hereinafter referred to as the CAMCE) is a vital livelihood project jointly promoted by the Chinese government and the Bangladeshi government.

3.2.2 Project Overview

Initiated by the Dhaka Water Supply and Sewerage Authority (DWASA), the Padma (Jashaldia) Water Treatment Plant Project is located in the suburb of Dhaka. With a total investment of USD 290.8 million supported by the preferential loans for foreign aid issued by the Chinese government, the project built a pumping station, a water purification plant with a daily capacity of 450,000 tons, a booster pumping station, double-circuit overhead high-voltage cables and 33 km-long large-caliber raw water and purified water distribution pipelines. The CAMCE was responsible for design, materials supply, construction, installation, debugging and training (Fig. 3.11).

Fig. 3.11

Aerial view of the water purification plant

The CAMCE signed a contract with the DWASA in September 2012 and launched the project on October 1, 2014, which passed the completion acceptation in January 2019, as all indicators met the requirements set forth in the contract. The project went into service and began to provide water to the urban area of Dhaka after it was connected with the water distribution networks in October 2019.

The project provides local residents with clean drinking water from surface water sources, and effectively boosts the capacity of surface water supply system of Dhaka, thus benefiting approximately three million local residents. At the same time, it has effectively controlled the geologic hazards resulting for the overexploitation of groundwater, and employed engineering approaches to realize water security and improve sanitation. In so doing, the project has made great contribution to bolstering local economic growth and protecting the ecological environment (Fig. 3.12).

Fig. 3.12

Sheikh Hasina, prime minister of Bangladesh, attended the completion ceremony of the project on october 11, 2019

3.2.3 Measures for Pollution Control

While implementing the Padma (Jashaldia) Water Treatment Plant Project, the CAMCE faced a series of acute problems including water pollution, solid waste pollution and noise pollution, so it took a range of effective measures to tackle these challenges for green sustainable development.

• (1) Measures for Water Pollution

  In order to alleviate the pollution to the groundwater environment generated by construction-related wastewater and domestic sewage, the CAMCE carried out classified collection and composition-based treatment of construction-related waste water, before discharging it to the nearby receiving waters. Domestic sewage was released to the nearby receiving waters after it was collected by a grease trap and septic tank and subject to ecological treatment. The waste mud generated in the course of construction was discharged to a mud pit and then subject to precipitation, and be discharged after meeting the standards.

• (2) Measures for Solid Waste Pollution

  The solid waste generated in the course of construction primarily comprised construction waste and household waste, which were cleaned and transported to designated dumping ground according to the rules for the disposal and management of construction waste and waste materials. The following measures were taken by the CAMCE to dispose of solid waste during the construction of the project. (1) Solid waste was stored by type at fenced and covered dumping ground and facilities with sufficient capacity, and subject to reinforced management. (2) Waste materials were recycled whenever possible to facilitate afforestation, road paving and the construction of other ecological landscapes. A landfill was set up on the construction site for construction waste and backfilled in a timely manner. Random dumping was banned. Domestic waste was subject to prompt and unified clearance. (3) When the project was completed, temporary construction facilities were dismantled and the remaining construction garbage and waste materials were cleaned, so as to ensure “all waste materials are removed from the construction site upon completion.”

• (3) Measures for Noise Pollution

  The CAMCE adopted strict measures to reduce and control noise to keep noise pollution under control and reduce the impact of noise on residents living nearby. As the construction was brought to an end, the impact of the noise was eliminated. It took the following measures to achieve that goal. (1) It employed high-quality soundproofing components to insulate the noise source of construction equipment from the environment to keep the construction noise enclosed in these components and narrow the scope and intensity of noise pollution. (2) It installed sound absorption panels made of fiber materials, granular materials and foam materials around noisy construction equipment like pile drivers and sawing machines. (3) Spring shock absorbers, rubber dampers, pipeline shock absorbers and damping technology were applied to the areas between construction equipment and the basic parts or connection points to cut momentum and reduce noise. (4) The CAMCE appropriately designed the layout of the construction site and set up fences for operation zones at all stages.(5) It employed professionals to operate low-frequency and low-noise vibrators for concrete pouring. Meanwhile, it made sure that vibrators were not submerged into steel or templates during the operation, so as to avoid strong noise-induced environmental pollution and prevent it from disturbing residents. (6) It reduced the noise of the steel templates during the vibration by replacing small steel templates with bamboo plywood.

The local department of environmental protection and a third-party environmental assessment agency performed two EIAs respectively in the early stage of the project and after the completion of the project, in line with relevant provisions of Bangladesh. Main conclusions of the EIAs are as follows:

• i. Assessment of environmental pollution: the pH scale of precipitated sludge discharged by the water plant is 7, so it can be used as backfill materials for the restoration of farmland and roads and poses no risk to the surroundings and people living nearby.

• ii. Assessment of the ecological environment: The water source of the Padma (Jashaldia) Water Treatment Plant Project in Bangladesh is the Padma River and the ecological environment along the river remains intact.

• iii. Assessment of status quo: The vegetation and grassland along the pipelines have been restored before and after the construction of the project. At the same time, the vegetation and grassland in the construction site of the water plant and those nearby were protected, according to the special environmental protection plan prepared before the commencement of the construction work. They were transplanted before excavation and maintained by designated personnel. After the completion of the project, they have been restored promptly.

3.2.4 Application of Green Technology

• (1) Frequency Conversion Technology for Water Pumps

  The Padma (Jashaldia) Water Treatment Plant Project has a daily water supply capacity of 450,000 tons. The clean water that meets relevant standards will be delivered to the water distribution network in the urban area of Dhaka through the 30 km-long transmission pipelines. Given that the temporal distribution of urban water consumption is uneven, the CAMCE considered frequency conversion technology regarding the design of intake pumps, delivery pumps and booster pumps. The frequency conversion technology for water pumps is an automated control technology that changes water flows by regulating the frequency of input power. Compared with previous valve regulation, it features less noise pollution, higher energy efficiency and higher operating efficiency, making great contribution to the utilization rate of water resources (Fig. 3.13).

  Fig. 3.13

  

  Aerial view of intake facilities

• (2) Recycling of Water for Production

  In order to increase the utilization rate of water resources and minimize the discharge of industrial wastewater to nearby natural water bodies, the project took the recycling of industrial wastewater into account by reusing the drainage of water for the backflushing of the filter after it met relevant standards through treatment. In so doing, it curtails the discharge of wastewater. At the same time, it also cuts the amount of water from the water source and keeps the water utilization rate of the plant under three%, thus laying a foundation for the water plant to seek environmentally friendly operation in the long run.

• (3) Design Philosophy of Sponge Cities

  In Bangladesh, there is intense rainfall in the wet season with frequent heavy rain and rainstorms. For this reason, external drainage has to draw on the concept of sponge cities. Therefore, “green” measures like sunken greenbelt and vegetation-covered shallow gullies for drainage were taken by the CAMCE. The idea is to drain water away slowly and disperse the source of drainage, so as to release the massive rainfall from the plant progressively through different channels during rainstorms. In this way, on the one hand, it reduces the use of mud dredging in the early stage of plant building; on the other hand, it reduces the massive use of pipelines, which is typical of traditional drainage networks. While curtailing investment in the project, this solution has also properly handled the challenge of drainage during the wet season.