Exide shut downs affect survey results
Greater Wellington Regional Council?s community monitoring of airborne lead levels around Exide?s Petone battery recycling plant show an improvement over 1999 levels. By Chrys Ayley A study of airborne discharges from Petone?s Exide plant show an improvement on 1999 levels but the results may not be atypical according to Greater Wellington Regional Council (GWRC). Environmental regulation manager Alistair Cross said the results of this year?s monitoring are useful but because the monitoring period coincided with several maintenance shut downs they did not get the quantity of data needed. During the sixty-one day study (February 1 to May 31 2008) of lead and arsenic discharges major maintenance work, including replacement of the furnace stack, took place. The furnace operated for 28 days and refining took place on 25 days. The study highlights that on about half the days that monitoring occurred the smelting and refining operations were shut down. Air samples were taken every second day at Waione and Kirkcaldy Streets. ?Median concentrations of lead in air were approximately one-third of the concentrations measured at the same site in 1999.? The study concluded that as a result of the shutdowns emissions of lead and arsenic particulate from Exide?s site during the monitoring period may not be atypical. ?The monitoring results may not be fully representative of longer term levels in air.? The lack of emissions normally associated with normal handling of battery scrap and other processing activities on site and the possibility of abnormal discharges associated with the maintenance work means the monitoring results may not be fully representative of local air quality during normal operations at Exide. Median lead concentrations at Waione Street were found to be two- thirds higher than those measured at Kirkcaldy Street and this is attributed to prevailing northerly winds transporting lead containing particulate from Exide to Waione Street. Arsenic concentrations in the air, which were measured for the first time, were not at levels to warrant concern. A longer period is needed for comparison with the national guideline for arsenic in air. GWRC communications advisor Matt Velde said it was confident about the results taken on the days the plant was operating although it did not anticipate the study would be affected so much by the shutdowns. The study will be repeated next year.
