GET WATER SMART
Want to conserve water on your construction project? Irish Water’s new guide offers advice on how businesses can better conserve and reuse water
Developed in partnership with the Construction Industry Federation (CIF), Sisk, Cairn Homes and the Irish Green Building Council (IGBC), Irish Water’s new guide details how builders and developers can implement sustainable and circular processes to achieve massive savings in water conservation.
To launch the new guide, Irish Water is now calling on sustainability representatives in industry to enrol in its upcoming Water Conservation Clinics, developed in partnership with the CIF, which will run this autumn. These free, in-person clinics will offer training and guidance in terms of how businesses can implement sustainable and circular processes at their sites to conserve water.
Many developers and businesses are already embracing these circular ways of working. Irish Water’s Water Stewardship Programme aims to help businesses lower their water use and operating costs while simultaneously helping protect the environment and companies such as Sisk Group, BAM Contractors and CBRE have already made huge strides through completing the programme.
For example, through working with Irish Water, Sisk Group has been able to save 10% more water through implementing Irish Water’s Water Stewardship Programme and various water reduction measures across its sites. Alan Cawley, Senior Sustainability Manager at Sisk, said: “Conserving water at our sites is key for Sisk and through working with Irish Water, we’ve been able to conserve 10% more water. Through rainwater harvesting, over the past year we’ve also been able to reuse more than approximately 1,000,000 litres of water, for everything from dust suppression and cleaning tools to developing thriving garden areas on our sites. We’re aiming to reduce our water intensity by 50% by 2025 over our 2019 baseline and with the support of Irish Water, we’re confident we will achieve this.”
TOP TIPS FOR WATER USE AND PLANNING IN CONSTRUCTION
PHASE 1: DESIGN
The most cost-effective approach to designing water-efficient homes is to incorporate water saving principles into the project from the beginning.
Prepare a water management plan for your project that includes:
• Actions during construction
• Appliances and plumbing to be installed
• Water reuse potential
• Landscaping and rainwater utilisation
• Include water conservation and water quality in all of your project tenders and contractual documents
• Specify water efficient fittings and appliances. These should reduce drinking water use inside the home to under 80 litres per person per day. Use the Water Efficiency Calculator from European Unified Water label to calculate water use per person.
• Stay up to date with the latest design and appliances to help water conservation
• Agree on a budget and procure funding. Check Enterprise Ireland programmes GreenPlus and Green Start for funding and grants
• If you are designing a greenfield site, use natural draining swales instead of costly concrete pipes
• Install drainage systems that allow the polluted ‘first flush’ to be diverted into trade waste
• The clean water that follows it can flow into tanks, pond systems or drainage swales.
Make water conservation a key objective of the project. Make sure everyone involved is aware of their responsibilities.
• Provide induction training for new employees and contractors. This should make them aware of the program benefits and their responsibilities
• Keep the water management plan on site and accessible
• Discuss water management at regular meetings
• Keep track of ongoing achievements
• Promote your achievements to local media and industry associations.
PHASE 2: DURING CONSTRUCTION
Construction companies can
minimise water pollution and maximise sustainability. To do this, they should follow environmental guidelines and adopt sustainable practices of their own.
Meter your water usage on site and use the water consumption hierarchy – prevent, conserve, reuse or recycle, potable water.
Use waterless systems like wheel washes and urinals, use brooms rather than hoses to clean paths and gutters and use offsite construction to reduce on site batching.
Purchase and install equipment with water saving measures and technology. Examples include percussion taps, twin flush and low water toilets. You can also retrofit water-saving technologies.
Reuse or recycle
There are many ways to collect water for reuse.
Rainwater harvesting systems – use these to collect water for use in dust suppression and vehicle or equipment cleaning.
Recirculating systems – use these for concrete washouts, cleaning tools and toilet flushing.
Dewatering activities – reuse water from this process for dampening roads, subject to pH adjustment.
Potable (drinking) water
Only use potable water as a last resort. If you must use it, then conserve, reuse or recycle.
• Maintain and fix systems to prevent leaks and drips
• Don’t leave taps running unnecessarily
• Reduce evaporation by retaining as much vegetation as possible
• Install water efficient irrigation systems
If water use is necessary, use high pressure, water-efficient trigger hoses for cleaning. Use buckets of water to clean tools instead of running water and monitor high water use areas on site directly, such as wheelwash and dust suppression. Use admixture in grey water for dust suppression.
Protect water quality
Avoid disturbing waterways, flood plains, vegetation and soil by planning ahead. Draw up your drainage plan before works start. It’s important that nothing from your site, such as soil, sand and cement slurry enters gutters or drains. Doing this will help avoid polluting the stormwater system, local streams and rivers. Here are some tips to do this.
• Sustainable Urban Drainage Systems (SUDS) should be specified in new developments. These minimise the volume and rate of water run-off from the site that could impact flooding elsewhere.
• Don’t put cement works on roads or paths to avoid the need to wash slurry away with water.
• Fence the site with temporary hoarding and line it with hay bales. Geotextile silt fencing can also be used.
• Install and maintain erosion and sediment control devices. Bales, contours, baffles, mounds or vegetation can reduce water velocities by redirecting runoff at regular intervals.
• Cover or filter stormwater inlets and drains.
• Monitor discharges to controlled waters regularly.
• Regularly clean and maintain all stormwater protection devices.
• Avoid the use of building materials such as asbestos or PVC, which will pollute water.
• Stockpile and cover building materials away from drains or roads.
• Restrict all materials and spill-risk activities to the least sensitive part of the site. That means the greatest distance from surface waters and drainage.
PHASE 3: POST CONSTRUCTION
How will people conserve water when using your building and surrounding areas in the long term?
Collect rainwater for storage and re-use in tanks, ponds, dams, swimming pools or underground tanks. The level of rainwater storage should be in proportion to household use.
Consider using greywater, which is water from sinks, baths, showers or clothes washers. You can recycle greywater to flush toilets or irrigate plants. You must maintain these systems to avoid poor quality water which is hazardous to health.
If you can’t use greywater now, design the plumbing to allow for adaptation.
Garden and landscape design
• Apply low-water use (Xeriscape) principles to gardens and landscapes
• Use water efficient irrigation systems
• Mulch flower beds and around plants
• Maximise infiltration of water to recharge groundwater
• Install rainwater collectors or water butts to collect water
• Use pool covers to minimise water evaporation
• Use native plants as they generally have low water requirements in their own climate.
Road and carpark design
Use natural drainage swales instead of costly concrete drainage pipes on greenfield sites. Harvest rainwater from car parks by avoiding the use of kerbing. Allow direct runoff into recharge zones. Recharge zones may be grassed or planted swales, permanent ponding basins or graded rock terracing. Design ground surfaces and paved areas to slope away from buildings and structures. This will enable water to run onto surrounding garden areas and recharge zones.Those interested in participating in Irish Water’s upcoming Water Conservation Clinics this autumn can sign up on Irish Water’s dedicated webpage – https://www.leanskillnet.com/training/water-conservation-clinic/
Irish Water’s new guide, Water Stewardship and Sustainability in Construction Sector, is available to view online here: water.ie/construction
Denise Maguire Editor of Irish Construction Industry Magazine & Plan Magazine
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