Safe and effective installation of rainwater harvesting systems

After the wettest winter since records began resulting in extensive flooding across the country, there is little doubt that we need to find better ways of managing water resources.

Climate change has dramatically altered our weather patterns, causing warmer, wetter winters and hotter, drier summers. This in turn has locked the country into drought/flood cycles, the impact of which has been considerably exacerbated by building on flood plains, over-abstraction from watercourses, and population growth. It’s a sobering thought that even after a winter like we’ve just experienced, some areas of the country are still expected to experience water stresses in the coming months.

In essence, as urban areas spread and the earth continues to warm up, the UK needs to have tailored, localised strategies both to reduce the impact of future droughts and to lower the risk of flooding.

The strategy needs to take account not just of removing the threat of floodwater, but also the need to store and reuse rainwater in-situ. In doing so, it will bring financial benefits to users, but also provide a much needed water source in drought.

WHY RAINWATER HARVESTING?

Part G of the Building Regulations now requires that water consumption is limited to 125 litres per person, per day. Capturing and recycling rainwater for non-potable uses such as flushing loos or cleaning clothes, can reduce the amount of water used within a domestic setting by more than 50%, and by up to 85% for a commercial building – which clearly also translates into lower water bills. The latter can also benefit from another government scheme – the Enhanced Capital Allowance; if it has been bought from a supplier within the scheme, the cost of the technology can be written off against tax during the year the investment was made (www.eca-water.gov.uk).

However, an interest in rainwater harvesting goes beyond a drive for more sensible use of mains water. Rainwater harvesting systems reduce surface run-off during heavy rainfall and pass the recycled water indirectly via WCs, washing machines etc. to the foul system rather than the storm drains, so that it poses no contribution to flood risk.

RAINWATER HARVESTING SYSTEMS – HOW THEY WORK

The operating principles for UK rainwater harvesting equipment are broadly the same.

Rainwater is collected from roof of the building and filtered before entering either an above or below ground rainwater holding tank.
The water can then either be pumped either directly to WCs and vehicle jet washes, or to a high level header/break tank within the building which will then service the non-potable appliances as per normal.

Systems that serve WCs or washing machines are automatically backed up with mains water at no inconvenience to the homeowner.
Those that comply with British Standard BS 8515 will be designed to meet minimum specifications while also allaying any concerns

about the possibility of cross-contamination of mains drinking water with rainwater.

DESIGNING A SYSTEM

We would always recommend bringing in technical experts and engineers from the company supplying the system at the very beginning of the project planning to assess your best options. Unfortunately, all too often this happens when the plumbing is already part complete which can mean costly rebuilding work to reconfigure the system.

SPECIFYING CORRECTLY

Selection of the correct size of storage tank is critical if the property is to comply with both BS8515 and the Code for Sustainable Homes.

The geographical location, annual rainfall, the area and type of roof or collection surface, and intended applications (now and in the future) are all considerations to ensure full compliance.

For domestic applications, the calculations are simple and can be safely estimated by using general storage sizing tables. These tables (contained within the Standard) equate roof area with annual average rainfall depth to determine a suitable tank capacity. Note: to comply with the Code, you must use the Code’s intermediate method of calculation.

Sizing of the tank should also take account of the ability of rainwater harvesting systems to reduce surface-water run-off and limit the risk of flooding, under SUR1 of the Code – our technical team can provide appropriate advice.

For more advice contact us on 01923 261660 or visit our website www.septictank-supplies.co.uk

Clearwater Septic Tank 2800L

The onion shape is the most popular septic tank in the United Kingdom to date and is highly durable and robust.

The Clearwater septic tank is manufactured by Kingspan Environmental (Klargester) and is made from Glass Reinforced Plastic (GRP)

The Clearwater septic tank comes in three sizes and is suitable for individual domestic dwellings up to a large family house.

EPP2 Certified Products, Click here to find out more

 

Capacity (Litres)	No. People (2001/head/day	Diameter (mm)	Inlet Level to Base (mm)
2800	4	1905	1565
3800	10	2070	1795
4600	14	2080	2035

• Made from composite GRP - strong, light, chemically resistant and watertight
• Press moulded shape provides wide, squat, form which makes the tank easy to install and handle
• Stable base for storage
• Shackles are provided to aid lifting and positioning within the excavation
• All unit volumes are designed in accordance with the recommendations given in BS 6297: 1983
• The new manufacturing process minimises styrene emissions and reduces waste - all the better for our environment

Conder Clereflo Bypass Separator: Area up to 1667 sq/metres

The CNSB3S/21 is suitable for an area of up to 1667

Class 1Separator including Silt trap

Bypass separators fully treat all flows generated by rainfall rates of up to 6.5mm/hr. These separators are used when it is considered an acceptable risk not to provide full treatment for high flows, for example where only small spillages occur and the risk of spillage is small such as on short stay car parks.

Features and benefits:

• Innovative design
• Small and easy to handle
• Competitively priced
• Fully compliant to the Environment
• Agency’s PPG3 guidelines
• Major installed cost savings
• Fully tested and verified with a range from CNSB 3s to CNSB 1500s (class 1)
• Full BSI certification
• Exceeds industry standards
• An Environment Agency verified manufacturer
• Easy to service

Process & performance

The Conder range of bypass separators is designed to treat all of the flow up to the designed nominal size. Any flow in excess of the nominal size is allowed to bypass the separation chamber thus keeping the separated and trapped oil safe. During the early part of a rain storm which is a time of high oil contamination, all of the contaminated water flow passes through a sediment collection chamber and enters the separation chamber through a patented oil skimming and filter device. This ensures that all of the oil proceeds to the separation chamber where it is separated to the Class 1 standard of 5mg/l and safely trapped. As the rain storm builds up to its maximum and the level of oil contamination reduces significantly, the nominal size flow continues to pass through the separation chamber and any excess flow of virtually clean water is allowed to bypass directly to the outlet.

Application areas:

• Car parks
• Roadways and major trunk roads
• Light industrial and goods yards
• Discharge to sensitive environment

Dimensions

• Length - 1.4m
• Diameter - 1m
• Height - 2.2m
• Access - 750mm
• Base to inlet - 1.7m
• Base to outlet - 1.6m

Bypass Separators

Bypass separators fully treat all flows generated by rainfall rates of up to 6.5mm/hr. This covers over 99% of all rainfall events. Flows above this rate are allowed to bypass the separator. These separators are used when it is considered an acceptable risk not to provide full treatment for high flows, for example where the risk of a large spillage and heavy rainfall occurring at the same time is small.

Surface water drains normally discharge to a watercourse or indirectly into underground waters (groundwater) via a soakaway. Contamination of surface water by oil, chemicals or suspended solids can cause these discharges to have a serious impact on the receiving water.

 

The Environment Regulators, Environment Agency, England and Wales, SEPA, Scottish Environmental Protection Agency in Scotland and Department of Environment & Heritage in Northern Ireland, have published guidance on surface water disposal, which offers a range of means of dealing with pollution both at source and at the point of discharge from site (so called ‘end of pipe’ treatment). These techniques are known as ‘Sustainable Drainage Systems’ (SuDS).

Where run-off is draining from relatively low risk areas such as car-parks and non-operational areas, a source control approach, such as permeable surfaces or infiltration trenches, may offer a suitable means of treatment, removing the need for a separator.

Oil separators are installed on surface water drainage systems to protect receiving waters from pollution by oil, which may be present due to minor leaks from vehicles and plant, from accidental spillage.

Effluent from industrial processes and vehicle washing should normally be discharged to the foul sewer (subject to the approval of the sewerage undertaker) for further treatment at a municipal treatment works.

Separator Standards and Types

A British (and European) standard (BS EN 858-1 and 858-2) for the design and use of prefabricated oil separators has been adopted. New prefabricated separators should comply with the standard.

Separator Classes

The standard refers to two ‘classes’ of separator, based on performance under standard test conditions.

Class I

Designed to achieve a concentration of less than 5mg/l of oil under standard test conditions, should be used when the separator is required to remove very small oil droplets.

Class II

Designed to achieve a concentration of less than 100mg/l oil under standard test conditions and are suitable for dealing with discharges where a lower quality requirement applies (for example where the effluent passes to foul sewer).

Both classes can be produced as full retention or bypass separators. The oil concentration limits of 5 mg/l and 100 mg/l are only applicable under standard test conditions. It should not be expected that separators will comply with these limits when operating under field conditions.

Mini Domestic Sewage Pumping Station

The mini Zoeller Z190 domestic sewage pumping station is a complete kit for use in areas where gravity flow is not available. The mini system is used for the transfer of sewage or waste water, all specially designed for easy installation.
All our pumping stations comply to BS EN 12050-1:2001 / BS EN 752-6:1998 standards. 

The mini Z190 is a small and compact sewage pumping station suitable for extensions, garden rooms and small applications. The vertical float will prevent any hang ups like you get in the standard float on a wire type system.

The standard domestic pumping station consists of the heavy duty cast iron Zoeller 222 (6m lift) submersible sewage pump with 50mm solid handling for peace of mind.

This sewage pumping station can pump up to 80m across to mains
 

Mini Z190 Sewage Pumping Station Includes:

1 x Zoeller 222 50mm solids sewage pump (up to 6m lift)

1 x 635mm x 610mm HDPE moulded basin

1 x 450mm dia Pedestrian rated cover (double seal)

1 x Soft close Non return valve

1 x Internal 50mm PVC discharge pipe work Kit

1 x Seal for incoming and outgoing pipework (4" & 2")

1 x 12 months warranty

Premier Tech Aqua Millennium Septic Tank

The smartest & shallowest septic tank to hit the market to date.

Conder Millennium

Invert

200 mm as standard - The Millennium Conder Septic tank is supplied complete with a 1 metre neck extension making the invert adjustable between 200mm and 1.2 met

Pre filter drastically prolongs lifespan of drainage field and has an automatic outlet cut off when cleaning the filter.

Benefits

• Low profile design for shallow dig.
• Durable polyethylene structure.
• Lockable pedestrian access cover.
• Variable invert level between 200mm and 1.2 metres.
• Pre filter prolonging lifespan of drainage field.
• CE approved and tested to EN12566-1
• Automatic outlet cut - off when cleaning filter

Klargester Sample Chamber

Half price Klargester/Clearwater sample chamber

This great offer of a half priced Klargester sample chamber is available when purchasing the following;

• Klargester Septic Tank
• Clearwater Septic Tank
• Klargester Pump Station
• Clearwater Pump Station
• Any Klargester Sewage Treatment Plant
• Any Clearwater Sewage Treatment Plant

Description

Sample chambers are larger than access chambers and inspection chambers, typically 500mm diameter and 1000mm deep. They provide access for maintenance equipment and are ideal rodding points.

Inspection chambers should not be confused with sample chambers, an inspection chamber will not allow for rodding or any maintenance.

The Kingspan sample chamber dimensions;

• Overal depth - 1333mm
• Inlet depth - 1093mm
• diameter - 490mm
• Inlet & outlet pipe diameter 110mm/160mm