Sustainable Building, Eco Development Techniques

Information resouce site for GREEN sustainable building development

Sustainable Sewage Disposal Solutions

As a global community, we MUST re-think the way that we dispose of sewage and wastewater.  Centralised sewage works are not sustainable.  They use vast amounts of electricity and are one of the biggest polluters of our rivers.  We must follow the lead given by many countries and de-centralise sewage treatment, with each house being responsible for its own wastewater solution.  Imagine if the only effluent that left a house was clean water?   We have to stop regarding sewage as a problem that must be solved and start to value the benefits that can be obtained from it.  This is the only way that it can become a sustainable process.

The problem with septic tanks and sewage treatment plants is that the end product is sewage sludge.  All sewage treatment plants produce sewage sludge which then has to be removed by tanker for further treatment at a sewage works, involving enormous amounts of electricity, to render it safe for disposal either to landfill sites or for agricultural use.

There is another way - Vermi-Composting.

A Vermi-Composter is the complete opposite, in process and ideology, of a sewage treatment plant.  Sewage treatment plants produce highly toxic sewage sludge and regard the sewage as a problem to be eliminated, wheras vermi-composting only produces natural compost and regards sewage as an asset.  Vermi-composting is an established technology in many parts of the world apart from the UK.

What is a Sewage Treatment Plant?

Sewage Treatment Plants range from the single house, 'three-tanks-in-one' package plant to the large municipal sewage works where each stage is in a seperate tank.  Raw sewage is settled in large tanks, the solids forming an anearobic sludge whcih requires further treatment, using more electricity and fuel for transportation, before it can be rendered safe for the environment.  The remaining liquid is aerated using vast quantities of air, normally supplied by electrical blowers, before being transferred to trickling media beds.  Rotating arms distribute the effluent evenly over the surface for further bacterial digestion.  It is then pumped to final settlement tanks before the cleaned effluent is discharged to a watercourse.

A sewage treatment plant produces methane, a major greenhouse gas, and cannot accept even mediocre amounts of organic matter.  At municipal works, sewage is first screened to remove it before it is transported to landfill sites for disposal.  Package plant owners are simply told not to flush it down the drains - but that is impossible to police and results in plant failure.

All sewage treatment plants use bacteria for the sewage treatment process.

All sewage and wastewater treatment plants adhere, in principle, to the above description of the process, except for the FilterPod, which is a non-electric sustainable sewage treatment plant and the only one that we would recommend.

What is a Vermi-Composter?

  It is a simple, single underground tank or even a plastic-lined hole in the ground that takes all the wastewater and organic waste, including cardboard, paper, food,  grass clippings, cabbage leaves, etc. from the house and garden, filtering the liquid from the solid waste material using natural humus as a filter.  It simply composts the solids using worms, beetles and other small invertibrates to convert the waste into humus which can be used directly as a garden fertiliser.  The filtered water is clean enough to be discharged directly to a stream or other watercourse.

Vermi-Composters are available for import from several different manufacturers - but are not yet manufactured in the UK.

The differences between a sewage treatment plant and a vermi-composter


Sewage Treatment Plant


 Only treats sewage and wastewater.  These are aerated together in a sewage 'soup' Composts sewage solids and all other organic household and garden waste.  It filters out the clean water, leaving the solids behind in the humus for digestion by the worms.
 Is a machine Is not a machine
 Aquatic Environment Required Non-Aquatic Environment is essential
 Produces sewage sludge Produces Compost
 Uses bacteria for the process Uses worms, beetles and other invertibrates for the process
 End product is toxic and requires further treatment to render it safe for use End product is non-toxic and may be used directly on the land
 Treats the wastewater and sewage together in one tank Filters out the wastewater and simply treats the solid organic matter
 Requires regular emptying of the sewage sludge by tanker  Never requires emptying as no sludge produced
 Electrical process Non-Electrical process
 Greatly affected by anti-bacterials in the wastewater Resiliant to anti-bacterials in the wastewater
 Waste produced is subject to the Environmental Permitting Regulations 2007 Waste produced is not subject to the Environmental Permitting Regulations 2007 

 A vermi-composter cannot be replaced by a sewage treatment plant as the system would not work.

Advantages of  Vermi-Composters

Unlike sewage treatment plants, vermi-composters offer a virtually zero carbon emission process.

They use exactly the same technology as a non-electric composting toilet, but on a larger scale.

 Organic household, sanitary and garden waste, which cannot be discharged into a sewage treatment plant and which is normally is viewed as a problem, adding to the enormous burden in landfill sites, is transformed into valuable compost for recycling in the sustainable garden.  Unlike sewage sludge, the compost produced is not subject to the Environmental Permitting Regulations 2007.  This means that the compost can be used directly as a fertiliser for all garden produce, turning a problem into a solution.

The use of a vermi-composter reduces the carbon footprint of the average family home by over 0.5 TONNES per YEAR when compared to a sewage treatment plant.

THINK before you order a sewage treatment plant - Why create toxic waste from a valuable asset?

Sewage System Installers

There are more 'Cowboys' out there, in this section of the building trade, than any other. It amazes me how many supposedly professional contractors have no idea of the rules and regulations concerning sewage system and their installation.

We suggest White Rose Installations Ltd. as a first contact for a sewage treatment system install. If they don't cover your area, they will know of a good contractor who does.

You may even be able to get the full cost of a new system paid for under a septic tank failure insurance policy claim under your Buildings Insurance.