Fig. 4
From: Assessment of stormwater discharge contamination and toxicity for a cold-climate urban landscape
Principal component analysis (PCA) biplots and proportions of variance for two scenarios including: A and B: pH, TDS, TOC/DOC, COD, fecal coliforms, TSS, sum of metals, sum of PAHs, 1/EC10 (algae), and 1/EC50 (Microtox) (Table 2; Additional file 1: Tables S5, S7, and S8); and C and D: pH, TDS, TOC/DOC, COD, fecal coliforms, TSS, and sum of metals (Additional file 1: Tables S5, S7, and S8). The dotted lines in B and D indicate the typical cut-off of 75% for total variance used in PCA