The new instrument will amend directions issued in 2001 (ENDS Reports 313, p 40 and 312, pp 6-7 ). Under these directions, sewage works serving an estimated 78% of the population-equivalent load must report their annual discharges of 65 substances where they exceed specified thresholds.
The latest amendment has been triggered by a change in requirements to report to the European Pollutant Emission Register. DEFRA is also taking the opportunity to bring the list of substances and reporting thresholds in line with other industries reporting to the inventory.
In total, 33 additional substances will be added to the sewage works list and 21 organic compounds will be removed. Reporting thresholds will be amended for a further 20 substances.
DEFRA does not intend that reporting should involve monitoring beyond that already required for other purposes. Discharges of substances which are not routinely monitored are to be estimated by sewerage undertakers using methodologies developed jointly with the Agency.
DEFRA says that, where there is no information on discharges of certain substances, and no recognised and appropriate way of estimating them, a report of "not applicable" will be acceptable. It remains to be seen how widely this option will be pursued.
Important additions to the reporting list are total organic carbon, nitrogen, phosphorus, chloride and fluoride. The inclusion of these bulk parameters will make the inventory relevant when assessing strategies to tackle problems such as eutrophication.
Organic chemicals added to the list include total halogenated organic compounds, chlorinated paraffins, polycyclic aromatic compounds, the pesticides chlorpyrifos and cypermethrin and the flame retardant hexabromocyclododecane.