New stormwater priority pollutants: comparison with international classifications, quality criteria and monitoring programs

Abstract

Stonnwater discharges are generated by rain runoff from land and impervious areas such asroads, parking lots, and roofs during rainfall and snowmelt events. It contains an array ofdifferent pollutants such as organic matter, particles, heavy metals, inorganic trace elementsand xenobiotic organic compounds (XOCs). It is important to consider the hazards concerningthese pollutants when considering design of monitoring strategies, comparing differenthandling strategies for stonnwater utilisation, treatment methods and discharge to receivingwaters.In the EU 5FP funded Daywater project a list of selected stonnwater priority pollutants(SSPP) was identified, which has been used for assessing pollutant sources and fluxes,behaviour and fate during passage through best management practices (BMPs) and theenvironmental risk associated with their subsequent dispersal. The methodology used;Chemical Hazard Identification and Assessment Tool (CHIAT) aims at selecting relevantSSPP e.g. and can be used for development and evaluation of monitoring programmes.The Daywater SSPP-list consists of water quality parameters (BOD, COD, SS, nitrogen, pHand phosphorus); metals (Cd, Cr, Cu, Ni, Pb, Pt and Zn); PAHs (naphthalene, pyrene andbenzo[a]pyrene); herbicides (pendimethalin, phenmedipham, glyphosate and terbutylazine);and other XOCs (nonylphenol ethoxylates, pentachlorophenol, di(2-ethylhexyl)phthalate,PCB-28 and MTBE) representing persistent, ubiquitous compounds and compounds derivingfrom specific anthropogenic sources.The list was compared with data found within the Danish nation-wide monitoringprogrammes for the aquatic environment (NOV A2003 and NOV ANA); European monitoringprogrammes; pollutant registers; individual European legislation; as well as quality criteriaand limit values. The comparison reveals differences since most of these are set on arbitrarycriteria or focuses on the current EU legislation. Overlaps was found with the studiedprogrammes, but also some "new" compounds was selected; platinum, herbicides and MTBEwhich indicate that revision of existing monitoring programmes is needed and that stonnwatercontains more hazardous pollutants than previously anticipated.