Influence of design and media amendments on the performance of stormwater biofilters

Biofiltration systems are a promising retrofit option for site-constrained urban areas due to the vertical arrangement of treatment stages that leads to a relatively compact footprint. Existing knowledge about the influence of their design and configuration on hydrological, stormwater pollutant removal and long-term performance is limited and this has been identified as a barrier to their widespread uptake. Long-term simulations of lined and unlined biofiltration systems in four contrasting UK climatic regimes were used to assess the influence of climate, ponding depth, biofilter to drainage area ratio and infiltration rate on hydrological performance. The results showed that local differences in climate have a significant impact on performance and that infiltration rates as low as 0·36 mm/h are not suitable for locations in the UK with high rainfall unless the biofilter to drainage area ratio is greater than 10%. However, with higher infiltration rates (72 mm/h) a biofilter occupying only 3% of the impermeable catchment area would be capable of infiltrating 97% of annual rainfall in central England. Preliminary results of adsorption and column tests to assess the effectiveness of media amendments, specifically zeolite and granular activated carbon, for dissolved copper and phosphate removal are presented in this paper

The effect of Smog-Ozone warnings and a vanpool program on traffic volume in york county of south carolina

Ground-level ozone is a critical criteria pollutant that is significantly generated by transportation patterns. We study the effect of smog–ozone warnings, triggered by the Environmental Protection Agency, on traffic volume in York County, South Carolina during the period 2006–10. In addition, the subperiods 2006–07 and 2008–10, where the ozone smog-alert thresholds 0.080 parts per million (ppm) and 0.075 ppm, respectively, are examined. The approach followed in this paper is a differences-in-differences (DID) regression. Additionally, a regression discontinuity design in the DID framework is applied. We find a negative and significant decrease in weekday peak-hour traffic volume in the treatment group during 2008–10

Evaluation of agricultural best-management practices in the Conestoga River Headwaters, Pennsylvania : effects of pipe-outlet terracing on quantity and quality of surface runoff and ground water in a small carbonate-rock basin near Churchtown, Pennsylvania, 1983-89 /

Shipping list no.: 97-0188-P.Includes bibliographical references (p. 61-62).Mode of access: Internet

Case study for delineating a contributing area to a well in a fractured siliciclastic-bedrock aquifer near Lansdale, Pennsylvania /

Shipping list no.: 2003-0141-P.Includes bibliographical references (p. 45-46).Mode of access: Internet