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GRAF Carat Septic Tank 3750L 11PE | G50078

£1,060.00
£1,272.00 (inc VAT)
£1,060.00 (exc VAT)

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Product Description

This product is delivered directly from the supplier, lead times vary.

 

The GRAF Carat 3750L Septic Tank is a dependable underground wastewater treatment solution designed for residential properties and small commercial installations without access to mains drainage. With a 3,750-litre capacity, this high-quality septic tank provides effective primary sewage treatment while delivering long-term durability and low maintenance requirements.

Manufactured from robust, corrosion-resistant polyethylene, the GRAF Carat tank combines exceptional strength with a lightweight design, making transportation and installation simpler and more cost-effective than traditional concrete systems. Its efficient internal baffle system helps separate solids from liquids, promoting effective wastewater treatment and reliable long-term performance. Designed for straightforward installation and minimal upkeep, the GRAF Carat 3750L is an ideal choice for off-grid drainage applications where reliability and environmental responsibility are essential.


Product Features:

  • 3,750L capacity for residential and small commercial properties
  • Lightweight design for easier handling and installation
  • Ideal for locations without access to mains drainage
  • Durable, corrosion-resistant polyethylene construction
  • Efficient internal baffle system for improved solids separation
  • Low-maintenance design with accessible inspection shafts
  • Suitable for challenging and remote installation sites
  • Long service life with reliable underground performance
  • Environmentally responsible wastewater treatment solution
  • Compatible with a variety of riser and lid options
  • Optional vehicle-duty lid rated up to 3.5 tonnes
  • Designed for dependable long-term sewage management

 

Typical Applications:

  • Domestic properties
  • Rural homes and cottages
  • Agricultural buildings
  • Small commercial premises
  • Holiday homes and lodges
  • Remote sites without mains sewer connections

 

Specification Value
Model G50078
Population Capacity Up to 11 People
Dimensions (L x W x H) 2280 x 1755 x 1590 mm
Weight (Empty) 150 kg
Tank Design Life 50 Years
Tank Warranty 15 Years


  Graf Carat 3750L Drawing
Graf Carat 3750L Installation Guide

 

SKU: TANSEPTGRA002

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Need help choosing the right tank? Call our team on 01388 537050.

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CUSTOMER REVIEWS

Rated 4.8/5 by Direct Drainage Customers

Based on over 600 verified reviews

VERIFIED REVIEW

Very helpful from the start to the finish

Items were despatched quickly and arrived the next day. Would recommend.

Title

North Hayne Farm Cottages | 26 June 2026

VERIFIED REVIEW

Cheapest price I could find for the pump

Cheapest price I could find for the pump and delivery the next day what more could you want.

Title

Sam Jukes | 5 November 2025

VERIFIED REVIEW

Great service!

I ordered a septic tank it was delivered within a week and the delivery driver left it in the exact right place and time. Would definitely use this company again, thanks so much.

Title

Eve Harland | December 2025

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FAQs

From choosing the right treatment plant to installation, maintenance and UK regulations, we've answered some of the most common questions to help you find the right solution for your property.

What is the difference between a septic tank and a sewage treatment plant?

A septic tank separates solids from wastewater before allowing the liquid to drain into a suitable drainage field. A sewage treatment plant goes a step further, using biological processes to treat wastewater to a higher standard before discharge. Sewage treatment plants are often the preferred choice where improved treatment performance is required.

What size sewage treatment plant do I need?

The correct size depends on the number of people your property is designed to accommodate, the expected wastewater flow and the type of property. Sewage treatment plants are commonly rated by Population Equivalent (PE). It's important to select a system with sufficient capacity to handle your property's requirements. Our team can help you choose a suitable system.

Do sewage treatment plants need electricity?

Most sewage treatment plants require electricity to operate components such as air blowers, pumps or control systems. However, power consumption varies depending on the manufacturer and model. Some systems use low-energy technology to help minimise running costs. Always check the individual product specifications before purchasing.

How often does a sewage treatment plant need emptying?

Sewage treatment plants require periodic desludging to remove accumulated solids. This is commonly carried out at least once a year, although the frequency depends on the system, usage and manufacturer's recommendations. Regular servicing and maintenance are also essential to maintain performance and help prevent costly breakdowns.

Do you supply replacement parts for sewage treatment plants?

Yes! At Direct Drainage, we supply a wide range of sewage treatment plant spare parts, including air blowers, diaphragms, filters and other essential components. Whether you're carrying out routine maintenance or replacing a faulty part, our team can help you identify a suitable replacement for your system.

Do you stock all tanks and sewage treatment systems?

We do not stock tanks and treatment systems as standard. These are supplied directly from the manufacturer. The lead times of these systems will vary. If you need an accurate delivery date, please contact us on 01388 537050.

Are your prices inclusive of VAT?

It is important to note that all prices listed on our website exclude VAT. VAT will be calculated at checkout.