Permeable pavement is an effective tool for improving stormwater hydrology and water quality when sited over soils with high infiltration rates, but its efficacy over less permeable soils is uncertain. This study examined permeable pavement performance when built over a low-conductivity, clay soil. Four parking stalls (50 m² total area) were retrofitted with permeable interlocking concrete pavement (PICP) to treat 15.2 m² of contributing impervious area (0.3:1 run-on ratio). Using an elevated underdrain, the site incorporated a 150-mm internal water storage (IWS) zone to increase exfiltration and promote anaerobic conditions for denitrification. From March 2014–April 2015, 22% of influent runoff volume was reduced via exfiltration and evaporation. Inter-event drawdown of the IWS zone created storage to capture and exfiltrate more than 70% of the runoff volume from precipitation events less than 8 mm, and peak flows were significantly reduced (median 84%). Relative to stormwater runoff from a nearby impermeable asphalt reference watershed, the permeable pavement produced significantly lower event mean concentrations (EMCs) of all pollutants except nitrate, which was significantly higher. Permeable pavement effluent and reference watershed runoff were 99%, 68%, and 96% different for total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP), respectively. Significantly lower permeable pavement effluent EMCs for copper (Cu, 79%), lead (Pb, 92%) and zinc (Zn, 88%) were also observed. The median effluent concentrations of TN (0.52 mg/L), TP (0.02 mg/L), and TSS (7 mg/L) were all very low relative to the literature. Sampling of nitrogen species in the IWS zone 12, 36, 60, and 84 h post-rainfall was done to better understand mechanisms of nitrogen removal in permeable pavement; results indicated denitrification may be occurring in the IWS zone. Effluent pollutant load from the permeable pavement was at minimum 85% less than from nearby untreated asphalt runoff for TP, TSS, Cu, Pb, and Zn, and was 73% less for TN. Permeable pavements built over low-permeability soils with internal water storage can considerably improve long-term hydrology and water quality.

透水路面位于渗透率高的土壤上时，是改善雨水水文和水质的有效工具，但其在渗透性较差的土壤上的功效尚不确定。这项研究检查了在低电导率的粘土上建筑时的渗透性路面性能。四个停车位（总面积50 m ²）进行了翻新，并采用了渗透性互锁混凝土路面（PICP），以处理15.2 m ²不可渗透面积的比例（0.3：1的增加比例）。通过使用高架的暗渠，该地点合并了一个150毫米的内部蓄水区（IWS），以增加渗出并促进厌氧条件进行反硝化。从2014年3月至2015年4月，通过渗滤和蒸发减少了22％的入水径流量。IWS区域的事件间降水创造了存储空间，以捕获和渗出少于8 mm的降水事件中超过70％的径流量，峰值流量显着减少（中位数为84％）。相对于附近不可渗透的沥青参考流域的雨水径流，可渗透的路面产生的所有污染物（硝酸盐除外）的事件平均浓度（EMC）明显较低，而硝酸盐则更高。透水路面流出物和参考流域径流分别为99％，68％，总悬浮固体（TSS），总氮（TN）和总磷（TP）的差异分别为96％和96％。还观察到铜（Cu，79％），铅（Pb，92％）和锌（Zn，88％）的渗透性路面废水EMC明显降低。相对于文献而言，TN（0.52 mg / L），TP（0.02 mg / L）和TSS（7 mg / L）的中位浓度均非常低。降雨后，在IWS地区12、36、60和84 h对氮物种进行了采样，以更好地了解透水路面中氮的去除机理。结果表明反硝化作用可能发生在IWS地区。TP，TSS，Cu，Pb和Zn的渗透性路面出水污染物负荷至少比附近未经处理的沥青径流少85％，而TN则少73％。