Manufacturers are developing ever more innovative brands of toilet paper, biodegradable sanitary towels and wipes. These are frequently disposed of down the toilet and into the sewerage system.
Water companies have practical concerns about the suitability of disposing of many of these so-called 'flushable products' into public and private drainage and sewerage networks rather than as municipal solid waste.
The associated problems include:
• an increasing number of sewer blockages
• foul odours
• sewer flooding
• environmental pollution1
• adverse impacts on pumping stations and sewage treatment plants.
Water UK has adopted in full the SNAP2 protocol to determine whether or not an individual sanitary or hygiene product is flushable in terms of foul drain and sewer disposal.
The water industry will not accept that a product is flushable unless it is compliant with the tests described within the SNAP protocol.
Water UK will seek to work in partnership with the producers of so-called flushable products and their trade associations (e.g. EDANA and INDA) in order to further develop the SNAP protocol as appropriate.
The water industry is determined to ensure that public sewers remain fit for purpose and will continue to support research into the effects of new product disposal, encourage an appropriate labelling regime and promote stakeholder and consumer education, in addition to helping and advising manufacturers.
Water UK will work with government, EUREAU and other stakeholders to promote coherent, integrated and sustainable waste management systems that support the role of water companies as sewerage undertakers.
The water industry supports the reduction, re-use and recycling of waste and will engage with and seek to influence key stakeholders in supporting our principle that sewers are for sewage – put all other waste in its proper place3.
(1) Environmental pollution can result from untreated sewage being discharged directly or indirectly into watercourses and estuarial or coastal waters. Such pollution downgrades the biological, chemical and aesthetic quality of rivers, streams and estuarial or coastal waters.
The natural flora and fauna can be adversely affected and faecal matter, foam, scum, oil and sewage-derived litter are particularly unsightly and odorous. A few species of micro-organisms can rapidly form massive biofilms in organically polluted water. This is collectively referred to as 'sewage fungus'.
In extreme cases the pollution can result in extensive fish kills. Pollution also raises particular concern as to public health impact in estuarial or coastal waters which have been designated as bathing, shellfish and recreational waters.
(2) The Water UK Sewerage Network Abuse Prevention (SNAP) group has reviewed, recommended and been tasked with moving forward the outputs from collaborative research undertaken by the Water Research Centre (WRc) relating to project CP311.
(3) It is not always appreciated that sewer systems were constructed as a public health function to reduce the incidence of potentially fatal waterborne diseases. Furthermore, it could be argued that the construction of these sewer systems, in the middle of the 19th century, did far more to improve the overall health of the nation than any of the more recent medical advances.
It is therefore important that sewer systems are allowed to function for their primary purpose. Unfortunately, sewerage networks have recently come under increased pressures due to the inappropriate disposal of all kinds of materials such as Fats, Oils and Greases (FOGS), so-called 'flushable products' and macerated and food wastes. This is referred to as 'sewer abuse'.
Furthermore, threats to sewers from such products come at a time when the need for sustainable housing is expected to result in lower water usage. While lower water use is welcomed, one of the negative side effects could be a reduction in the ability of a drain/sewer system to be flushed clean of solids and 'sewer abuse' items, and also when the number of misconnections is rising significantly.
This situation is unprecedented. Already the ability of sewers to perform their primary functions may become compromised because sewer blockages cause flooding and pollution.