Communal & Residential Greywater Recycling

Quick explanation

1. Gravity transports greywater to the system.
2. Preliminary filtration removes large debris (like hair).
3. Greywater enters biological treatment tank for oxygenation.
4. Oxygenation helps the growth of beneficial bacteria.
5. Fine hollow fibers filter out bacteria and viruses.
6. Treated greywater is stored in clean tank for distribution.

Detailed explanation

Pre Filtration 

Greywater is transported from collection points within bathrooms across the building via a separate network of pipes. Not only does this eliminate the potential for cross-contamination, but it also allows the possibility of heat exchange technologies to recover heat from the waste greywater. Collection occurs via gravity. 

Preliminary filtration removes undissolved contaminants from the greywater supply including hair and textile fibres. On Stormsaver Systems, preliminary filtration is supplied with a high-pressure backwash feature which supplies processed greywater to provide self-cleaning to the preliminary filtration device. 

Biological Treatment

Greywater then enters the biological treatment tank.

The biological treatment process introduces aeration to naturally degrade organic contaminants such as shower gels and foam. The biological treatment tank also contains growth bodies to separate biofilm from the greywater. Growth bodies are designed to increase the surface area within the tank for biofilm to attach. 

Sedimentation

Aeration assists suspended solids in settling on the base of the treatment tank via sedimentation. These are removed via an efficient sludge pump. 

Ultrafiltration 

Greywater is then processed through ultrafiltration. Ultrafiltration processes greywater through hollow fibres to separate any remaining microbiological particles such as bacteria and viruses (rated to 0.02 microns). The automatic self-cleaning process includes a short backwash of the ultrafiltration device to remove contaminants for the best possible water quality. The control panel fully automates this process for complete peace of mind. 

Storage 

Treated greywater is then transferred a separate clean water tank for storage until required. A low nutrient load from the biological treatment process and removal of solid particles ensures greywater can be stored for extended periods. 

Mains water topup

Where limited greywater is available, an automatic mains water backup will continue to provide a water supply to outlets. The mains water backup is achieved through a WRAS-compliant air gap in the clean water tank. The process is fully automated by our control panel. 

Water Availability

Water scarcity is a growing problem for the UK.

Population growth, continued expansion of the built environment, and climate change are causing significant challenges for water supplies. The UK Environment Agency has estimated that an additional 5 billion litres per day will be required to meet demands in the next 25 years.

Greywater Recycling can help us to solve these challenges by providing a sustainable water supply for non-potable use in residential buildings.

Discharge Rates

Wastewater accounts for a significant proportion of total water discharge from a building. Once water is discharged, it enters the drainage network.

Much of the UK sewer infrastructure transports wastewater and stormwater together causing frequent overflows into surrounding water courses.

Greywater Recycling can effectively reduce wastewater discharge rates by facilitating the reuse of bathroom greywater.

Greywater Recycling can provide a non-potable water supply for many common water uses within residential settings. These cover…

• Toilet flushing
• Vehicle washing facilities
• Laundry
• Cooling
• Living wall irrigation

Greywater Recycling is well suited to high-density residential properties. Water use in residential settings is difficult to reduce due to the requirement for consumer habit changes. Relying on Greywater Recycling removes the need for behaviour changes and contributes towards reduced litres per person per day figures (LPPPD).  The below buildings are well suited to Communal Greywater Recycling.

• Apartments
• Student accommodation
• Hotels

Communal Greywater Recycling takes advantage of a single, commercial-style system for residential properties to collect and reuse bathroom wastewater for the provision of a non-potable water supply. 

• Remove ownership and maintenance responsibilities from the homeowner to a management organisation.
• Remove internal components from homes, assisting with reduced risk of cross-contamination between the greywater and mains water supplies.
• Prevent homeowners from switching the system off due to a lack of knowledge.
• Utilise commercial-grade components for an extended lifespan.
• Mitigate the need for consumer behaviour changes in water usage by supplying them with greywater.