Green infrastructure (GI) stormwater control measures (SCMs), such as permeable pavement systems, are common practices used for controlling stormwater runoff. In this paper, two permeable pavement strips were studied to quantify their water quality performance. The quality monitoring was coupled with comprehensive rainfall analysis to investigate the effects of common rainfall characteristics on the quality performance of the systems. The pavements utilized deep aggregate layers to promote higher infiltration, and were installed in parking lanes of an urban neighborhood. Water quality samples were collected from upgradient stormwater runoff and from stormwater captured by the permeable pavements. In addition to total suspended solids (TSS), nutrients, and dissolved metals, this research also investigated bacterial contamination (Escherichia coli, E. coli). The results indicated that the two permeable pavement systems significantly reduced concentrations of TSS, E. coli, total phosphorus, and ammonia. The average reductions of TSS and E. coli between the two systems were 47% and 69%, respectively. It was also observed that pollutant loadings in the stormwater runoff, as well as pollutant reductions, were affected by the intensity of sampled rainfall events. Thus, it is suggested to consider the effects of rainfall characteristics when reporting the water quality benefits of stormwater GIs.

This study presents the infiltration performance of two permeable pavement systems installed in the parking lanes of an urban neighborhood. Both systems were subject to large (12.9 and 9.8) impermeable drainage ratios and high sediment loadings from the surrounding environment. The surface infiltration performance of each system was monitored by conducting surface infiltration measurements and analysis of data collected using an array of embedded time domain reflectometers. The results indicated progression of clogging from the upgradient edge toward the downgradient edge on the surface of the permeable pavements, which limited the infiltration performance of the systems. This study conducted three different maintenance methods to restore the surface infiltration performance of the clogged permeable pavements. The developed monitoring techniques were used to ascertain the short-term and long-term efficiency of each surface maintenance treatment. The most effective maintenance treatment was determined to be a combination of hydro pressure washing and vacuuming to clean the permeable pavement surfaces. The research results indicate that the infiltration performance of permeable pavement systems, even those subjected to high hydraulic loadings and unsuitable environments, can be maintained with frequent application of a proper surface-maintenance method.

This research assesses the performance and methane production of a novel combined system for treatment of high-strength organic wastewater. The proposed system is composed of a rotating biological contactor (RBC) process under anaerobic conditions, in conjunction with a moving-bed biofilm reactor (MBBR) as the combining aerobic process. Various operational parameters were tested to maximize the chemical oxygen demand (COD) removal performance and methane gas production from treating high-strength synthetic wastewater. The identified optimal parameters include hydraulic retention time, organic loading rate, and disk rotational speed, equal to 5 days, 7 rotations per minute (rpm), and $2\mathrm{kg}\mathrm{COD}/{\mathrm{m}}^3/\mathrm{day}$ , respectively. Under these conditions, the combined system achieved high removal efficiency (98% from influent COD of $\mathrm{10,000}\mathrm{mg}/\mathrm{L}$ ) with the additional benefit of methane production [$116.60\mathrm{L}/\mathrm{day}$ from a 46-L anaerobic rotating biological contactor (AnRBC) reactor]. Also, analysis of kinetic models of experimental results from the AnRBC stage indicated the suitability of the Stover-Kincannon model with a prediction accuracy of 93%. The results confirmed the effectiveness of integrated AnRBC systems in achieving both high removal efficiency and methane production. Thus, this system is recommended for treating high-strength organic wastewater.

The Louisville Metropolitan Sewer District (MSD) has entered into a Consent Decree Agreement with U.S. EPA to reduce the number and volume of combined sewer overflows (CSOs) from the existing combined sewer system (CSS). As an aspect of this agreement MSD is using green infrastructure (GI) stormwater controls to reduce CSOs. The initial phase of the project is implementing GI controls in a small urbanized neighborhood (28 acres) in Louisville, KY, in lieu of a planned concrete retention basin. In December 2011, two permeable interlocking concrete pavement (ICP) controls were constructed. To quantify surface infiltration and subsurface exfiltration performance each control was embedded with time domain reflectometers (TDRs), thermistors, and piezometers. To predict the hydrological performance of the GI controls, a spreadsheet model is developed by utilizing each control's drainage area, hydraulic conductivity values for surrounding soil layers, and dimensions of each GI control. The model calculates the inflow and outflow volumes and predicts the water level inside the control for each rain event. Hydrological performance is defined as a GI control's ability to capture the runoff volume (infiltration capacity) and then pass captured volume into the underlying soil layers (exfiltration performance). The model's predicted water levels are compared with the recorded water levels by the embedded pressure transducers. The developed model predicts the ideal performance of the GI control and compares it to recorded data. This assessment technique works to quantify the progression of clogging at the surface and within the infiltration gallery. This model provides a method for monitoring the hydraulic performance of the GI controls over time.