Preventing Water Pollution: Best Practices For Construction Sites

Construction sites are often located near homes, and the materials used in construction can generate air, water, soil, and noise pollution. Water pollution from construction sites is underestimated and can have severe environmental consequences. It can cause internal illnesses in humans and animals that come into contact with the contaminated water, poison aquatic life, destroy natural habitats, and disrupt ecosystems. Globally, construction is a significant contributor to emissions and waste, and construction companies must adopt more environmentally sound practices to minimize water pollution and maximize sustainability.

Prevent soil and silt from entering watercourses

Construction sites are often located in close proximity to homes, which means that the materials used and the activities carried out can generate pollution that affects nearby residents. Water pollution from construction sites is a serious issue that can have a significant environmental impact. Soil and silt can enter watercourses through surface runoff, which can lead to siltation and cause severe environmental harm.

To prevent soil and silt from entering watercourses, it is important to control erosion and sedimentation. This can be achieved through a variety of measures:

• Vegetative Cover: Retaining and restoring vegetation cover is an effective way to stabilise soil and prevent erosion. This can include sodding, seeding, and mulching to establish new vegetation on bare ground.
• Erosion Control Blankets: Organic and biodegradable geotextile blankets can be used to control erosion until permanent vegetation is established. They can also be used in combination with seeding to enhance soil stability.
• Silt Fences: Temporary barriers made of geotextile fabric can be placed around soil stockpiles and along the sides of streams and ponds to intercept sediment-laden runoff, reduce runoff velocity, and retain sediment on-site.
• Settlement Units and Lagoons: These are commonly used to treat muddy water on-site, but they may not be effective in removing the smallest sediment particles. However, their treatment power can be enhanced using various techniques, such as Gel Flocculant anionic flocculants or Silt Net.
• Polymer Soil Amendments: Polyacrylamides (PAM) are polymer soil amendments that can help bind soil particles together, reducing erosion and sedimentation. They can be applied using hydroseeding equipment for seeding, fertilising, and mulching disturbed ground.
• Site Planning and Assessment: Conducting site assessments to identify areas vulnerable to erosion and drainage issues is crucial. Identifying key areas that require protection, such as areas with stripped vegetation or topsoil, can help prevent water from picking up high levels of silt.

By implementing these measures, construction sites can effectively prevent soil and silt from entering watercourses, reducing their environmental impact and minimising the risk of legal consequences.

Avoid topsoil clearance and cut and fill activities in winter

Construction sites can be a significant source of water pollution, and it is important to take steps to avoid this. One such step is to avoid topsoil clearance and cut and fill activities during the winter months.

Topsoil clearance and cut and fill activities can result in the spread of contaminated materials, which can then be washed into nearby waterways, leading to water pollution. During the winter, frozen ground can cause equipment slippage and make excavations difficult or impossible. Frozen soil can also result in material stockpiles freezing, making it challenging to achieve adequate compaction or uniformly distribute materials.

To avoid these issues, it is recommended to develop a winter construction plan that addresses shutdown procedures or active construction plans. This plan should aim to complete all winter shutdown activities before frozen conditions set in, ideally before any snowfall. It is crucial to stabilize all slopes and areas of bare soil using rock, permanent or temporary vegetation, mulch, or erosion control blankets. Additionally, fertilizer, liming materials, and soil additives should never be applied to frozen ground, and their application should be postponed until after the spring snow melt.

By following these guidelines, construction sites can minimize the potential for water pollution caused by topsoil clearance and cut and fill activities during the winter months.

Control dust with water sprays, on-tool extraction, or vegetation

Water sprays are a temporary dust control option that can be used to control dust at construction sites. Water trucks with spray nozzles can be used to spray a fine mist of water over construction sites and haul routes, weighing down dust particles and causing them to settle, thus limiting their potential to become airborne. Water sprays can also be used as on-tool dust suppression systems, where a shroud directs water onto the tool and limits the amount of dust that escapes into the air. This method requires regular maintenance and operator training to ensure proper use and compliance with safety standards.

On-tool extraction is another method to control dust. This method involves fitting an exhaust to tools that remove dust as it is being produced. This may be a better option than on-tool water suppression in remote areas without a water source, as it minimises manual handling and the risk of injuries.

Planting vegetation, such as grass, trees, or mulch, around construction sites can also help control dust by stabilising the soil and preventing dust from becoming airborne. Vegetation provides environmental benefits such as wildlife habitat and improved aesthetics. Additionally, vegetation acts as a natural filter for generated pollution, reducing the amount of pollution that nearby residents may come into contact with.

Store fuel tanks away from vehicle routes and access points

Construction sites are often located in urban and rural areas, close to homes, and the materials used and activities carried out on these sites can generate pollution. Water pollution from construction sites is a serious issue that can have severe environmental consequences, including contamination of groundwater and surface water near the site.

One important way to control water pollution at construction sites is to properly manage fuel and chemical storage. Fuel and chemical spillages can have a devastating impact on watercourses, killing fish and plant life and rendering water undrinkable. To prevent accidental spillages, it is crucial to store fuel tanks away from vehicle routes and access points. Here are some detailed guidelines to achieve this:

• Establish a designated storage compound for fuel and chemicals, located at a safe distance from vehicle routes and access points. This compound should be positioned in a secure area, away from any water sources or drains, to minimise the risk of vandalism and accidental collisions.
• Use heavy-duty traffic barriers to separate the fuel storage area from vehicle routes and operation areas. This will provide an extra layer of protection against collisions and reduce the risk of spillages.
• Ensure that all fuel storage tanks are bunded, meaning they are placed within a larger container that can capture and contain any spillages that occur during loading or in the event of tank damage.
• Store fuel and chemical containers in a secure, locked area, with clearly labelled tanks and lids to prevent unauthorised access and reduce the risk of vandalism.
• Regularly inspect hoses and connections for leaks and faults, and use drip trays to capture any small spillages that may occur.
• Keep a forklift readily available on-site to facilitate the safe and efficient movement of fuel tanks in case of an emergency.
• Train site staff in the proper use of spill kits and emergency response procedures in the event of a significant spillage. Ensure site managers receive specialist environmental training to handle fuel and chemical storage effectively.

By implementing these measures, construction sites can significantly reduce the risk of water pollution caused by fuel and chemical spillages, minimising their environmental impact and complying with relevant regulations.

Treat and repurpose water waste

Construction sites are often located near homes, and the materials used can cause water pollution. Water pollution from construction sites is underestimated and has the potential to cause severe environmental problems. Construction companies can treat and repurpose their water waste to minimise pollution and conserve water.

One example of water waste treatment technology is Alfa Laval's range of centrifuge decanters, which are designed to meet the stringent environmental demands for solid-liquid separation in tunnelling construction. This technology removes fine particles, making it easier to meet requirements for water disposal or reuse. It also reduces the costs of transporting untreated water away from the site.

Another example of water waste treatment is the use of decanters by Alfa Laval, which offer effective and cost-efficient rain and groundwater treatment. These decanters are supported by a welded box beam frame with main bearings at both ends, and the bowl, conveyor, casing, and other parts are made of stainless steel.

In addition to treating water waste, construction companies can also take action to reduce their water footprint. For example, they can require the use of erosion control blankets, sedimentation ponds, and silt fences on project sites to limit pollution. They can also train their employees to pick up debris and trash, control erosion, and maintain equipment.

By adopting more sustainable practices and treating and repurposing their water waste, construction companies can play a crucial role in conserving water and protecting the environment.

Frequently asked questions