Water Recycling

Water Recycling: A Comprehensive Guide For Business

Saving money will always be a top priority for businesses of all kinds and now, as the climate crisis deepens over time, saving the environment will become increasingly important for all industries and sectors.

In order to develop operational resilience and protect bottom lines, it is now essential for organisations to include environmental factors in risk assessments, taking the entire supply chain into account.

One of the biggest areas of concern with regards to environmental breakdown is water.

Businesses now need to consider both water quantity and water quality, and what they can do to safeguard resources for future generations, as supplies come under increasing pressure from climate change, pollution, urbanisation, population growth and water mismanagement.

The good news is that there are many ways in which business water footprints can be reduced… and water recycling is one such strategy that can make a significant difference to your environmental impact.

What is water recycling?

Quite simply, water recycling is the process of purifying treated wastewater (from everyday activities like irrigation, vehicle washing, laundry and toilet flushing) so that it can be used as a supply source once again.

With the normal water cycle, resources are drawn from rivers, aquifers and reservoirs and then processed for human use, removing any potentially harmful substances.

Once this water has been used, it becomes wastewater. This is sent to a wastewater treatment plant before being released back into the environment to start the cycle all over again.

With water recycling, wastewater that would typically be sent back into the environment undergoes more advanced processing so it can be used elsewhere. This helps make communities become more drought resilient through being less reliant on rainfall.

For companies, water recycling represents a sustainable way to enjoy cost savings over the long term, operate more efficiently, conserve resources and minimise their environmental impacts, as well as enhancing their reputation in an increasingly competitive business landscape.

How is water recycled? A Step-by-step guide

Water recycling includes an extensive treatment process to achieve the requisite water quality standards for safe onsite use.

Step 1

Screening/separation using course screens or filters removes large solids from wastewater. From there, dissolved air flotation systems or lamella settlement tanks are used to remove fine particles.

Step 2

Wastewater is treated either aerobically or anaerobically (or a combination of the two). Anaerobic digestion is typically recommended as biogas is a byproduct, which can be used to generate power and heat elsewhere onsite.

Step 3

Further filtration can take place (depending on need), either using reverse osmosis or ultrafiltration to improve water quality.

Step 4

Water purification treatment occurs using processes like distillation, UV or deionisation, removing bacteria and other impurities that membranes can’t filter out.

What are the different types of water recycling?

The best type of water recycling system will depend on the specific needs of your business and your specific scale of operation. Different strategies to consider include:

Greywater recycling

Greywater recycling systems capture water from showers, sinks, washing machines and so on for reuse elsewhere. Greywater is cleaner than blackwater (from toilets) and can be treated through filtration and/or disinfection to remove impurities.

Greywater can be used for non-potable purposes, including:

• Cooling systems
• Outdoor cleaning
• Toilet flushing (in place of freshwater)
• Irrigation (including gardens, lawns and landscapes)

This would be a good choice for any organisation with significant water consumption, such as hotels, hospitality businesses, laundromats, leisure centres and so on.

8 FAQs about greywater:

What are the rules for greywater in the UK?

Greywater reuse must be carried out in compliance with relevant building regulations, with systems professionally designed and installed to ensure that they adhere to strict water safety standards.

Is rainwater classed as greywater?

Rainwater and greywater are different. Rainwater is a natural part of the water cycle, falling from the skin as rain and, as such, contains no contaminants from the ground or soil. It can be harvested to be used in various applications, including toilet flushing and car washing.

Greywater is wastewater from sinks, baths, showers and washing machines that doesn’t contain sewage or contaminants from toilets (known as blackwater).

What are the risks of using greywater?

Widespread use of greywater can mitigate the risks posed by climate change and an insecure water future, as well as the sewage overflows.

However, research shows that greywater isn’t safe to ingest, so systems should ensure that greywater is kept in pipes, or allowed to soak into the ground to prevent ingestion.

There are also possible environmental impacts to consider, as greywater may impact plant biomass nutrition, soil enzyme activity and worm avoidance, as well as affecting water quality through algal bloom development and pathogen spread. Because the water contains contaminants, soils, plants and aquatic ecosystems can all be put at risk.

Is greywater the same as wastewater?

Ultimately, yes – greywater can be considered a form of wastewater, generated through the use of non-toilet appliances and fixtures.

Wastewater from the kitchen sink and dishwasher isn’t greywater, however, because of the presence of pollutants like fats, oils and food particles.

How much water does greywater recycling save?

Greywater can make up between 30 and 50 per cent of wastewater discharged into sewers. Reuse systems have been found to reduce water consumption by up to 40 per cent.

How much greywater does a washing machine produce?

In domestic settings, greywater production can account for between 50 and 80 per cent of the total volume and, within this, laundry process wastewater can represent up to 24 per cent of residential effluent.

In Europe, up to 60 litres of treated water is consumed in each washing cycle. And in industrial laundries, approximately 15 litres of water is used to wash 1kg of clothes, with around 400m3 of greywater produced each day.

How do I maintain a greywater system?

Regular maintenance is required on all greywater systems to ensure that they continue to serve you well over the long term. Always check the specific manufacturer’s guidelines for full maintenance advice.

Typically, pumps and filters should be inspected and cleaned at least once a year, while full system flushes are recommended annually, as well.

It is also advisable to carry out periodic inspections of plant and soil health to ensure that irrigation-related increased alkalinity isn’t affecting nutrient uptake.

Is greywater reuse better than blackwater?

Finding the right kind of water recycling system for your business can be difficult.

Blackwater reuse technology often comes with higher upfront cost, as well as higher operation and maintenance costs. However, you can make greater water savings over time, as well as greater carbon emission savings.

Blackwater volumes will always be greater than greywater volumes because there are more sources included. It is important to weigh up the volume of recycled water demand against the volume of wastewater supply when deciding which system is best for you.

For example, if you only need to use recycled water for laundry and toilets, a greywater system would certainly be sufficient.

Rainwater harvesting

Rainwater harvesting involves capturing and storing the rainwater that falls on roofs and other hard surfaces, filtering it so that it can be used in applications, such as:

• Cleaning (equipment, machinery, outdoor areas, vehicle washing)
• Cooling systems
• Landscaping

This is a particularly good option for any businesses with sites in places that see heavy frequent rainfall, or which have high water costs.

7 rainwater harvesting FAQs

How does rainwater harvesting work?

The starting point of your rainwater harvesting system is the roof of your building (or buildings).

Rainwater lands on the roof and runs down a pipe into a storage tank, passing over a filter to remove leaves and other debris. If this debris isn’t filtered out, it can rot and spread diseases, affecting water quality and rendering supply unusable.

Water is stored in the tank until it needs to be used. There are different sizes of tank available, with something to suit every budget and volume demand. Larger storage systems can be installed below ground if required.

Harvested water can be either pumped to an appliance (where it passes through another filter) or to a header tank. This water can’t be used for drinking purposes.

What are the benefits of rainwater harvesting?

Benefits of rainwater harvesting include cost savings on business water bills, increased resilience against climate change and drought, and protection for the environment through reduced soil erosion and stormwater runoff.

It will also make your business more sustainable and reduce the risks of urban flooding.

What are the limitations of rainwater harvesting?

One of the biggest drawbacks of rainwater harvesting systems is the fact that they’re dependent on rainfall patterns. During dry periods, harvesting will be minimal or nonexistent. This means it can’t be relied upon as the only water source.

Rainwater can also be contaminated by pollutants, pathogens and debris from collection surfaces. If it’s to be used as potable water, significant treatment may be required.

Which is better: Greywater reuse or rainwater harvesting?

Which of these strategies is best for you and your business will depend on what your specific water needs are, what the local climate is and how much space you have available.

Both are highly effective as water-saving solutions, but the H2o Building Services team can help you work out which is most appropriate for you.

What are the economic benefits of rainwater harvesting for businesses?

Direct financial savings can be enjoyed through rainwater harvesting, which helps to reduce water bills significantly as you won’t be as reliant on mains water. You will also be more resilient against water price hikes and supply restrictions.

Reduced maintenance costs can also be a benefit, as rainwater is naturally soft, so limescale buildup in systems is reduced. Furthermore, you will improve your reputation as a sustainable company, attracting eco-conscious consumers.

How do I choose the right rainwater harvesting system for my needs?

Important factors to consider when looking at rainwater harvesting systems include:

• Tank size
• Above or below ground storage
• Roof size (the bigger the better)
• Tank location (taking into account weight)
• Downstream drainage system
• Potential demand
• Future usage

What are the top manufacturers of rainwater harvesting equipment?

Top manufacturers to research include:

• Kingspan
• Rainharvesting Systems
• Storm Saver
• GRAF

Industrial water reuse

For a more advanced onsite option, consider investing in industrial water reuse systems.

This would be beneficial for any companies involved in industrial or manufacturing processes (such as factories or plants), using technology like ultrafiltration, reverse osmosis or chemical treatment.

Typical applications for this type of water recycling strategy include:

• Process water (rinsing, heating or cooling in manufacturing)
• Closed loop systems
• Boiler feedwater

4 Industrial water reuse FAQs

What are the best practices for industrial water reuse?

Begin with a water audit so you can understand your consumption needs to better decide which water reuse solutions would be most appropriate.

From there, you will see which treatment technology would be most effective, whether that’s filtration, reverse osmosis or chemicals, depending on the required water quality in question.

Run pilot tests to make sure that treatment systems deliver the results you need before implementing them site-wide.

Monitor water quality using automatic sensors over time to ensure that you’re operating at optimum efficiency to achieve your sustainable and financial goals.

How does industrial water reuse impact water scarcity?

Water scarcity can be reduced through industrial water reuse, as alternative reliable water sources to mains water are available, driving down the need to extract and transport new water.

Using treated wastewater provides a predictable supply of water, particularly in drought-stricken regions and places where water stress is an ongoing concern.

How does industrial water reuse impact water quality?

Quality control is essential in water recycling, as there is the potential for new contaminants from industrial processes to be introduced.

Existing contaminants may also be concentrated during reuse procedures. Appropriate treatment standards must be maintained to prevent potentially negative impacts for people and the natural environment.

However, the positive impacts outway the negative and water recycling can ultimately support resource conservation, reduce pollution, protect ecosystems and overall water quality, save businesses money and support the transition to a circular economy.

How can I maximise water reuse in manufacturing processes?

Manufacturing processes use a lot of water, so finding ways to conserve resources is essential. For example, it takes 2,866 gallons of water to make just one pair of jeans. And it takes 39,000 gallons of water to produce the average car.

Process water is often only used once during manufacturing, but it doesn’t have to be this way – and given that industrial water consumption is only expected to increase in the future, the time is now to look for ways to maximise reuse efficiency.

Closed loop water reclamation systems are particularly effective, as they aim to reclaim all water used.

For example, equipment can be cleaned without disassembly, with water from the final rinse recirculated and used as the pre-rinse elsewhere, as well as being used for clean-out-of-place operations.

Or you could look into zero liquid discharge engineering, where you put measures in place to eliminate liquid waste from leaving your site at all so that water remains in circulation for as long as possible. Reverse osmosis filtering is the typical go-to method here.

And, as ever, equipment upgrades and proactive maintenance programmes will ensure that you maximise efficiencies, reducing loss and waste.

How cost effective are different water recycling technologies?

Greywater recycling

Greywater recycling requires installation of treatment plant and supply infrastructure, which can represent a significant investment.

However, there is no one specific way to carry out cost-benefit analysis that accounts for local context and is applicable to all reuse/recycling projects.

These systems can vary significantly in size, complexity and requirements. Greywater reuse reduces mains water consumption, as well as reducing the volume of water discharged into sewers.

If you have a water meter fitted, you could save on both water supply and wastewater bills.

Further cost savings can be enjoyed via BREEAM and the Home Quality Mark scheme, where points are awarded for water reuse.

Water companies may also offer incentives and strategic agreements relating to infrastructure connections and driving down water consumption.

The service sector generally has the most to gain from investing in greywater recycling systems, including commercial sites, leisure centres, hotels, hospitals, local authorities and schools.

Susdrain research suggests that the capital and operational costs of commercial systems can be significant, but they are considered to represent high system efficiency.

Capital costs range between £40,000 and £150,000, with operational costs ranging from £1,000 to £7,000 per annum.

In terms of savings, greywater recycling systems can provide between 30 and 50 per cent of the water requirements of the average office or warehouse building.

In some instances more than 50 per cent of water requirements can be provided: offices (75-86 per cent) and apartments/hotels (51 per cent).

Greywater reuse volumes in such commercial settings range between 3,000 and 17,000m3 per year, with annual cost savings of between £10,000 and £40,000.

Rainwater harvesting

Harvested rainwater is an alternative water source to mains supplies, reducing reliance on mains water and the associated costs.

The level of savings will depend on how much rainwater is collected, the quantity of potable water saved and whether you have a water meter installed onsite.

In all, commercial consumption accounts for approximately 20 per cent of all mains water supplies. As such, there is significant scope to use rainwater for irrigation, toilet flushing and other activities in commercial sites.

Greater savings are typically higher for businesses than domestic sites because they have larger roof areas and greater demand for non-potable water.

In terms of system costs and potential returns on investment, this will largely depend on your specific requirements and your own site factors.

This includes whether you’re retrofitting an existing building or working on a new development, where the storage tank will be situated and the scale of the project.

In general, prices of rainwater harvesting systems go up as the collection area and demand increases.

Costs for larger commercial systems can range from between £8,000 and £70,000 for a 5m3 and 100m3 storage tank respectively, according to Susdrain figures.

Typically, installing systems in a new build is cheaper than retrofitting, which will require excavation and changes to existing plumbing arrangements.

The overall cost effectiveness of these systems for businesses is site specific and will depend on current water charges (the higher the cost, the bigger the benefits) and maintenance costs.

What are the UK regulations/standards for water reuse?

Improving your water stewardship as a business is commendable but water recycling strategies must be implemented in compliance with all relevant regulations and standards. These include:

The water supply (water fittings) regulations 1999

These regulations apply to England and Wales, relating to the design, installation and maintenance of plumbing systems within both residential and commercial properties. Their aim is to prevent waste, misuse, over-consumption, contamination and erroneous measurement of water.

BS EN 16941-1:2018

This British standard sets out the requirements for the design, installation and maintenance of rainwater harvesting systems.

BS8525-1:2010

This British standard provides recommendations on the design, installation, alteration, testing and maintenance of greywater systems.

Case studies of successful water recycling initiatives worldwide

Fredericia Brewery, Denmark

Carlsberg Denmark’s Fredericia brewery successfully saved around one billion litres of water in two years, thanks to a water recycling system that recycles 90 per cent of all process water from production.

The water recycling plant makes this brewery the most water efficient of its kind in the world, with learnings taken from it to enable the company to achieve its target of eliminating waste water entirely by 2030.

It will also help the brewery drive down its energy consumption by ten per cent through its own biogas production and recirculation of hot water.

Tiruppur cluster, India

The Tiruppur cluster in India serves as the country’s biggest knitwear hub, accounting for 55 per cent of its total knitwear export.

It is also now making a name for itself as a sustainability pioneer, treating 140 million litres of effluent each day and achieving 96 per cent water recycling and reuse rates.

It uses zero liquid discharge technology and common effluent treatment plants to achieve its goals, with excessive water usage reduced to such an extent that groundwater levels have been restored to 100ft.

Water conservation practices also include meters, sewage treatment plants, push taps and sprinkler systems to minimise water wastage, alongside rainwater harvesting technology that often meets up to six months of factory requirements in just one heavy downpour.

FrieslandCampina, Belgium

FrieslandCampina is one of the biggest dairy companies in the world and is paving the way for sustainable water reuse and caustic recovery.

It recently partnered with Veolia Water Technologies to conserve water and recover valuable resources via a system integrating membrane filtration, evaporators and crystallisers tailored to suit the specific needs of the dairy industry.

Wastewater generated by dairy production is treated and reused for cleaning, equipment sterilisation and irrigation.

Waste disposal costs are also reduced thanks to the evaporators and crystallisers, which separate water from dissolved solids to recover products like salts, proteins and lactose.

The future of water recycling: Technological advancements & societal shifts

Technology in water recycling

As with most industries and sectors, the Internet of Things and artificial intelligence are expected to shape water recycling in the future.

This will be achieved through the use of smart sensors and connected devices to drive water quality monitoring in real time, as well as system performance and flow rates.

AI, meanwhile, will optimise treatment processes through data analysis, supporting predictive maintenance systems and reducing energy consumption.

Digital twin technology is also going to become more commonplace, with virtual replicas of physical systems brought in to simulate and analyse processes and procedures.

This ensures that decision makers are better able to identify potential issues, plan routine maintenance programmes more effectively and optimise performance across the board.

For businesses, the benefits include reduced costs through increased operational efficiency.

Elsewhere, decentralisation of wastewater treatment systems is expected to come increasingly to the fore, treating water closer to the source to reduce the need for water transport over long distances.

Technological advancements that will take centre stage include membrane bioreactors, anaerobic digestion and advanced oxidation processes.

And interest in nature-based solutions such as bioreactors, green roofs and constructed wetlands will gain further traction as time goes on, treating wastewater through natural processes.

This will reduce both energy consumption and operational costs, and deliver additional benefits for the natural environment, such as carbon sequestration and habitat creation.

Societal attitudes

Public perception of water recycling and wastewater reuse is one of the biggest challenges preventing widespread adoption of such measures.

Studies show that emotion, subjective norms, fairness and health risks have significant impacts on behavioural intentions.

Identified factors underlying the negative emotions obstructing recycled water use for drinking included gender, a heightened sense of pathogen disgust and being less educated.

In general, public concern over pathogens was identified as the main driver of emotional reactions towards water reuse.

However, studies also show that social acceptance of water reuse is now starting to shift, with figures from Cranfield University showing that, in the Netherlands, the use of recycled water for drinking is now supported by 75 per cent of people.

This compares to 67 per cent in the UK and 73 per cent in Spain.

Furthermore, there is also no higher support for eating food grown using recovered nutrients from wastewater in all three countries.

In order to forge ahead with this progressive shift in societal opinion, it is likely that communication interventions will need to focus on addressing public fears surrounding the health risks associated with potable water reuse.

Water conservation: Call H2o Building Services today!

Water recycling strategies aren’t just great for the environment. They’re great for businesses, as well.

The H2o Building Services team of experts can provide you with all the water recycling solutions you need, potentially saving you up to 50 per cent on water costs while increasing BREEAM ratings for public sector buildings.

We use a combination of automatic meter reading and rainwater harvesting processes to  provide you with a successful strategy to improve your water footprint, saving water and money at the same time.

To talk to one of our water audit experts, get in touch with the team today.

Commercial Water Recycling – Infographic

More than a billion people around the world now face the threat of being displaced by the year 2050 because of new ecological threats, conflict and civil unrest, with sub Saharan Africa, South Asia, the Middle East and North Africa facing the biggest number of dangerous environmental changes.

Download Water Recycling Infographic (PDF)