Odour from Sewage Works

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CONTROL OF ODOUR AT WASTE WATER TREATMENT WORKS

Introduction

The Scottish Parliament has introduced legislation to regulate odour release from Waste Water Treatment Works (WWTW). The Water Services (Scotland) Act 2005 gave Ministers the power to introduce a code of practice for assessing, controlling and minimising sewerage nuisance from the public sewerage system. The code of practice came into force on 22^nd April 2006.

The local authority is required to:

inspect certain WWTW at least once every year for the purpose of ensuring that the operator is complying with the code of practice.

investigate complaints made by residents living within the authority’s area regarding odour from WWTW

What does this mean for operators of WWTW?

It means that operators of WWTW, whether it is Scottish Water or a Private Financed Initiative (PFI) company, must comply with the code of practice. The code of practice sets in place a set of standards which are management-based controls to ensure that a WWTW is operating as efficiently as possible with respect to odour release.

If the local authority determines that the operator is not complying with the code, they are required to serve an enforcement notice. This notice will require the operator to put measures in place for complying with the code within a given timescale.

Failure to comply with an enforcement notice is an offence and the operator would be liable to a fine (if convicted) not exceeding £40,000. This legislation puts odour firmly on the WWTW operator’s agenda where previous legislation did not.

In order to comply with the code they must ensure that their site operates efficiently and that they have an Odour Management Plan in place.

What does it mean for residents?

Any resident who feels that the odour from a WWTW is a nuisance should contact their local Environmental Health Section and they will investigate on their behalf. Where they determine that the operator is failing to comply with the code of practice they will take formal action against them.

Does this mean there will never be odour from a WWTW again?

No. The requirement on the operator is to minimise nuisance not completely eliminate it. It would not be realistic to expect a completely odour-free WWTW without massive capital expenditure.

There may be occasions when WWTW cause odour through no fault of the operators, such as when there is a pollution incident and chemicals are illegally deposited in the sewer system. This can seriously disrupt the biological processes at the plant and lead to odour emissions from the site.

What this legislation is expected to do is to ensure that management of the site is efficient and that they are doing all that can reasonably be expected of them with regard to prevention of odour emissions.