Water is an essential component in construction. It influences both the quality of materials used and the site’s environmental impact.
This blog outlines the importance of water quality for construction to ensure structural durability and prevent pollution.
Table of Contents
Water in Concrete Production
Water is a fundamental ingredient in cement concrete, the backbone of most construction projects. Water not only governs the hydration of cement but also affects the consistency and overall quality of the mixture. When it comes to concrete production, poor-quality water can lead to several issues, such as:
Diminished compressive strength of the concrete.
Delayed or premature setting due to impurities in the water.
Reduced durability from high chloride or sulfate content may cause reinforcing steel corrosion.
Increased permeability, allowing water ingress that could damage the structure over time.
Surface defects, such as cracks or an uneven finish.
Water Quality Parameters for Concrete
To ensure the integrity of concrete, the water used should be clean and free from harmful substances. Potable water (water safe for drinking) is typically considered safe for concrete production use. However, in many cases, using alternative sources may make more financial sense. These water sources must be tested to meet specific standards before use.
One of the most critical standards in water quality for construction is BS EN 1008:2002 (adopted in Ireland as I.S. EN 1008:2002). All producers of concrete must comply with this regulation. The standard provides guidelines and defines acceptable limits for impurities, for example:
For sugars, phosphates, nitrates, lead and zinc, water can alternatively be shown to be suitable through setting time and strength testing. The initial setting time must be at least one hour and the final setting time no more than 12 hours (each within 25% of a control made with distilled or de-ionised water), and the 7-day compressive strength must be at least 90% of the control.
The standard also classifies water by its source:
- Potable water: considered suitable, with no testing required.
- Water recovered from concrete production (e.g. from washing out mixers): generally suitable, but must meet additional requirements.
- Underground water, natural surface water and industrial wastewater: may be suitable, but must be tested.
- Sea or brackish water: may be used for concrete without reinforcement or embedded metal, but is generally not suitable for reinforced or prestressed concrete.
- Sewage water: not suitable for use in concrete.
Construction & Water Pollution
Water quality management goes beyond concrete production. Poorly managed construction activities can result in water pollution. Different pollutants are often generated during construction activities, which can wash into nearby water bodies (e.g., lakes, rivers, seas). Some of the main pollutants to watch for when testing water leaving a construction site are:
Sediment: Construction activities can leave soil and other materials exposed to stormwater, which may wash pollutants into nearby water sources.
Chemicals and Oils: Any chemicals, fuels, or oils spilt on-site can easily contaminate nearby water bodies if not contained and managed properly.
Water Monitoring to Prevent Pollution
The EU Water Framework Directive (2000/60/EC) (WFD) is the primary legislation governing water protection across the EU, including pollution control in construction. In Ireland, it is implemented through national legislation, and construction companies are responsible for ensuring that water leaving their site does not cause pollution. Under Section 3 of the Local Government (Water Pollution) Acts, it is an offence to cause or permit polluting matter to enter waters. Failure to comply can result in legal consequences, including heavy fines.
Construction sites require a water monitoring strategy to ensure compliance with environmental regulations. Regular monitoring of water runoff ensures that water quality standards are maintained. A robust monitoring system helps identify issues early so corrective actions can be taken before any major environmental damage occurs.
Monitoring should be proportionate to the risk on site. Common parameters for water leaving a site include turbidity (an indicator of suspended solids), pH, and oils and hydrocarbons. Samples are typically taken at the discharge point and, where a site borders a watercourse, upstream and downstream of it. Monitoring points may need to change as the project progresses.
When to Test Water Quality for Construction
For Concrete Production: Water testing is essential for concrete production to ensure compliance with BS EN 1008:2002. For all non-potable water sources, testing should be done before first use along with follow-up tests. These follow-ups should be conducted based on the water source. For example, seawater should be tested annually, while industrial wastewater should be tested monthly. Samples should be at least 5 litres, representative of the water to be used, collected in a clean, sealed container, and tested within two weeks of sampling.
For Pollution Control: Similarly, frequent water quality monitoring is crucial to control and prevent pollution and comply with the EU Water Framework Directive (2000/60/EC) (WFD). Depending on the level of risk, monitoring may be required at different intervals. These intervals can range from hourly (if pollution is suspected) to just after significant weather events such as storms.
Best Practices for Water on Construction Sites
To protect both the quality of the water used in construction and the surrounding environment, consider the following best practices:
Educate the Workforce: Ensure that all staff understand the role water plays in the context of construction and pollution from construction activities.
Test Water for Construction: Water to be used in construction practices (e.g. concrete mixing) should be tested to make sure it’s safe to use.
Control Runoff: Preventative measures should be implemented to avoid contamination of local water bodies. For example, barriers or vegetation may direct water away from sensitive areas.
Manage Waste Properly: Dispose of solid, liquid, and sanitary waste responsibly. Store waste in secure containers and prevent leakage or spillage.
Test Runoff: Regularly test water leaving the construction site to avoid contamination and ensure compliance.
Conclusion: Water Quality for Construction
Water quality plays a pivotal role in both the durability of structures and the prevention of pollution at construction sites. Through water testing, construction companies can ensure their projects are successful and sustainable while adhering to regulations.
Here at Southern Scientific, we specialise in accurate monitoring of water quality for construction with low turnaround times. With 30+ years of experience, INAB accreditation (registration 194T), ISO 17025 and 10,000+ drinking water samples analysed per year, our team of experts can empower you to make informed decisions with the water at your construction site.
For concrete mixing water, see our water testing for construction service. For site runoff, see our water monitoring service.
