Rules change on small works

Significant changes to rules on small wastewater treatment systems come into force next month. Alex Best of wastewater specialist WPL warns of the dangers of being unprepared, and considers the implications

From July 2008, compliance with BS EN 12566-3:2005, which covers small wastewater treatment systems for up to 50 population, will become a legal requirement in the UK.

It will relate to plants with tanks made of concrete, steel, PVC-U, polyethylene, polypropylene and glass-reinforced polyester. Packaged or site-assembled domestic wastewater treatment plants must all comply with the new standards of sewage treatment efficiency.

BS EN 12566-3 is the British version of the European-wide harmonised construction products standard, which replaces all national standards. From July 2008, only sewage treatment plants which have been type tested and approved to the new standard and CE marked can be marketed in this country.

Merchants and other suppliers will not be able to sell non-compliant products. And those involved in specifying and installing such equipment must ensure that it complies with the new requirements from the due date. Trading Standards will enforce the regulations to ensure non-compliant treatment plants are not sold or installed.

It is, therefore, vital that all links in the supply chain understand their obligations under BS EN 12566-3, from architects and consultants to installers and merchants. All those involved in selecting wastewater treatment systems should specify or order compliant products or they may find that it may not meet the full requirements of the European standard.

Such an error could disrupt a build schedule and prove costly in terms of the specifier’s reputation and contract delays – so there is a lot at stake for all parties. By considering a package sewage treatment plant that is CE marked, these potential problems will be avoided.

Products that bear the CE mark reassure the purchaser that the product meets all the essential requirements of relevant European directives relating to health and safety. But what does CE accreditation mean when it comes to wastewater treatment systems?

Independent tests are done to assess the system’s sewage treatment efficiency and ensure it meets the required process performance standard. The levels of BOD5 (the amount of dissolved oxygen consumed in five days by biological processes), suspended solids and ammonia NH4-N are all tested for a specified volume of incoming standard effluent to determine the plant’s efficiency.

The WPL Diamond sewage treatment plant, for example, has been verified as fully compliant by independent assessment through Lloyds Register of Quality Assurance (LRQA), and carries the CE mark. It offers self-builders, architects and specifiers a wastewater treatment solution that meets current and future regulations.

The CE effluent-testing programme of WPL’s Diamond system was conducted over 38 weeks and the unit was one of the first to be tested and to have its design and build successfully type tested. The Diamond’s sewage treatment efficiency is verified to “clean” wastewater to a standard of 20mg/l BOD5 and 30mg/l suspended solids on a 95 percentile basis.

WPL has further demonstrated compliance by commissioning LRQA to undertake ongoing independent verification of its CE testing and approval process. Also, WPL’s ISO 9001 approved integrated management system guarantees repeatability of build quality.

The imminent introduction of BS EN 12566-3 will set new standards for small sewage treatment plants in the UK. At WPL says it is already prepared for these changes, and believes it is essential to ensure that other areas of the industry are ready too. The message is clear – prepare now or face potentially costly consequences.

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