GRAF One2Clean 18 Person Sewage Treatment Plant
Product code
From £4,004.31 Exc VAT (£4,805.17 Inc VAT)
Product Description
The GRAF One2Clean 18 Person Sewage Treatment Plant is supplied as two linked 6,500 litre Carat tanks. Splitting the volume across two standard tanks keeps the dig shallower than one large tank, which helps on sites with rock or a high water table.
It suits small developments, groups of holiday lets and busy farm sites. The two tanks sit side by side, so plan for an excavation of around 5.3 metres by 2.2 metres.
How the One2Clean Plant Works
The One2Clean 18 Person Sewage Treatment Plant treats wastewater in one tank using a simple three-stage cycle. First, sewage flows straight into the biological zone, with no pumping, and air flows through the whole tank so that bacteria start breaking down the waste.
Next, the control unit stops the air and the activated sludge settles to the bottom, leaving a layer of clear water on top. Finally, a one-piece clear water lifter draws off the treated water and the cycle starts again.
There are no pumps, moving parts or electrical parts inside the tank. Instead, the compressor and control unit sit above ground, where they are easy to reach for servicing. As a result, there is very little in the wastewater that can wear out or fail.
Key Features
- Very low energy use, from 0.63 kWh per day
- No pumps, moving parts or electrics in the tank
- Tested effluent quality of 7 mg/l BOD, 14 mg/l suspended solids and 0.5 mg/l ammonia
- Simple, compact control panel
- Quiet operation, so it suits gardens close to the house
- Lightweight Carat tank, easy to lift into place without a crane
What’s Included
- Two 6,500 litre GRAF Carat tanks with internal treatment parts fitted
- Clear water lifter and aeration system
- Air compressor and control unit
- Mini dome shafts with 150kg pedestrian telescopic lids
Options
- Traffic Telescopic Lid 3.5 Tonne, for driveways and parking areas
- Internal Pumped Outlet, for sites where the outlet cannot fall away by gravity
- External Cabinet M, for the control unit and compressor when there is no garage or outbuilding to house them
In addition, a raised outlet (fitted before dispatch), a warning beacon and a high level alarm are available on request. Please call us to add any of these to your order.
Where Can the Treated Water Go?
Treated water from the plant can usually discharge to a drainage field or, in many cases, to a ditch or stream. In England, the General Binding Rules set out when you can do this without a permit, so check the rules for your site or speak to the Environment Agency before you order. In Scotland, Wales and Northern Ireland, the local environment regulator sets the rules.
Specification
- Population: up to 18 people
- Tank: Two 6,500 litre GRAF Carat tanks
- Dimensions: 5280 x 2190 x 2390 mm (L x W x H)
- Weight: 440 kg
- Loading: Pedestrian as standard, vehicle with the traffic lid
- Tank warranty: 15 years, with a 50 year design life
- Parts warranty: 1 year from commissioning, or 3 years with an annual service
- Manufacturer: GRAF UK
Commissioning and Delivery
A GRAF-accredited engineer commissions the plant free of charge once it is installed, which also starts the warranty. We deliver the One2Clean 18 Person Sewage Treatment Plant free to UK mainland addresses. However, the plant arrives on a lorry, so you will need to be able to offload it on arrival. You can also download the drawing, data sheet and installation manual from this page.
Delivery and Returns
Delivery Information
Shipping costs for standard postcodes within UK Mainland are calculated at checkout when a postcode is entered.
Delivery charges are based on current manufacturer and courier rates. In some cases, delivery costs may be subject to confirmation after an order has been placed due to supplier delivery zones or freight changes. If an additional delivery charge applies, the customer will be notified before the order is dispatched and given the option to proceed or cancel the order for a full refund.
Some areas may incur additional charges, including:
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Scottish Highlands and Islands
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Isle of Wight, Channel Islands, Isle of Man, Anglesey, Western Isles, Shetland Islands, Orkney Islands, Isles of Scilly
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Northern Ireland
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Republic of Ireland
Additional charges may apply for postcodes in these areas:
AB, BT, CA, CT, DD, DG, EH, FK, G, GY, IM, IV, JE, KA, KW, KY, LD, LL, ML, PA, PH, PO 30–41, SA, SY, TD, TN, TR, ZE
If your postcode is listed above, please contact us before ordering for a shipping quote.
Some products are only available for delivery within England & Wales; this will be stated on the product page. If you are outside this area, please contact us for a quotation.
Delivery Lead Times
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Refer to individual product pages for expected delivery times.
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Custom orders may take longer; please enquire before ordering.
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Items on the same order may be delivered separately due to stock locations.
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If delivery is delayed, we will notify you via email.
Delivery Method
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All deliveries are kerbside unless stated otherwise.
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For larger items, customer offloading may be required.
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Someone must be available to receive and inspect the goods.
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Goods may be left in a safe place at the customer’s risk; Online Tank Store cannot accept responsibility once goods are left.
Note: By signing for the goods, you confirm that the outer packaging is intact and free from visible damage. Any visible damage must be noted on the delivery paperwork or the delivery refused.
Scheduled delivery times may be accommodated; please add instructions in the Customer Notes section at checkout.
Missing or Faulty Items
If items are missing or arrive damaged:
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Contact us within 48 hours of delivery at [email protected]
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Provide:
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Order number
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Photos of the goods
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Brief description of the issue
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We may require images for the manufacturer to provide replacements.
Delivery Charges & Returns
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Ensure the product is the correct size and suitable for your intended use.
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Standard tanks (no customisation) are returnable but subject to a restocking charge and must be returned in A1 condition. Returns may be expensive due to size and weight; please check before ordering.
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Failed delivery attempts: After one unsuccessful delivery attempt, items will be returned to the depot, and redelivery charges may apply.
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Special or custom tanks are non-returnable. If the wrong product is ordered or the item is no longer required, it cannot be returned, and no refund will be issued.
Returns & Refunds
Our full returns and refund policy can be found by clicking here.
It is important to us that the items you order are correct for your needs however, we understand that situations and requirements can change. It can be costly to return an order so please ensure you are certain of your requirements before you order and that you have read the returns policy above for details.
Custom Tank – An order is considered ‘custom’ when a non-standard configuration or colour is requested. Custom orders are not eligible for return so please ensure the product is what you require before ordering. By purchasing, you are agreeing to the above terms.