Urban Surfaces as Sources of Stormwater Pollution : An Evaluation of Substances Released from Building Envelopes

• Stormwater is an important transport pathway for pollutants from the urban environment into receiving water bodies, and, thus, it contributes to the deterioration of urban surface waters. The aim of this Licentiate thesis was to advance the understanding of the contributions of urban stormwater pollutants from building surface materials, and evaluate the implications for stormwater quality. Furthermore, this thesis also aims to (i) identify which pollutants can be expected to be released from building surface materials that are commonly used in the urban environment and (ii) estimate the magnitude of released pollutant concentrations in comparison to those from other important sources (e.g., those related to transportation, industries or atmospheric deposition). The material presented in the thesis includes a critical literature review of the sources of stormwater pollution, as well as laboratory and outdoor pilot studies of the pollutants released from commonly used building surface materials.  It was identified in the literature review that the current state of knowledge varies between source categories. Metallic building envelopes were early recognised as one of the major sources of metals in stormwater and, in many larger cities, they were identified as one of the main contributors of e.g., Cu, Pb and Zn to stormwater. Many building surface materials are also important contributors of pesticides. Recent research suggested that building surface materials (roofing membranes, plastic materials, concrete, paints and coatings, etc.) were important sources of organic micropollutants, but relatively few studies reported on such micropollutant releases from specific materials, or their concentrations in runoff. Results from the outdoor pilot study indicate that several of the 10 materials studied may contribute environmentally relevant concentrations of chemical substances commonly found in stormwater. Specific building surface materials were shown to be important sources of such metals as Cu and Zn: in the outdoor pilot study copper roofing sheets released Cu into rainwater at average concentrations of 3090 µg/L, zinc sheets released average Zn concentrations of 7770 µg/L, and galvanised steel released average Zn concentrations of 3530 µg/L. These concentrations exceed those measured from other sources (e.g., road runoff) by more than an order of magnitude. Moreover, nonylphenols (NPs) were released from PVC membranes, and bitumen shingles and felt. One of the PVC materials tested released, on average, NP concentrations of 26 µg/L, which were of the same order of magnitude as concentrations measured in road runoff. The same PVC also released an average concentration of 455  µg/L Diisononyl phthalate, DINP, but too little of data was available for comparisons to others sources. When comparing the laboratory leaching and outdoor pilot experiments, laboratory studies were efficient in identifying pollutant sources, and studying the effects of specific influential factors, but only the outdoor study produced realistic approximations of the released concentrations and loads of pollutants.  

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Vattenteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Water Engineering (hsv//eng)

Keyword

VA-teknik

Urban Water Engineering

Centre - Centre for Stormwater Management (DRIZZLE)

Centrumbildning - Centrum för dagvattenhantering (DRIZZLE)

Publication and Content Type

vet (subject category)

lic (subject category)