|
N
<br />Table 3. Results of two-tailed Wilcoxon rank-sum tests for comparison of selected field properties and water-quality constituents in wells by aquifer type, land use, and
<br />individual septic disposal system (ISDS) or non-ISDS area, Fraser River watershed, 1998-2001.
<br />[All water-quality constituents are in the dissolved form except for total coliform bacteria, methylene blue active substances, and radon-222. n, number of samples; Troubl. Fm., Troublesome
<br /> Formation;
<br />p-value is the significance level of the two-tailed Wilcoxon rank-sum test. A p-value less than or equal to 0.05 (shown in bold type) indicates that the hypothesis of similarities in
<br /> values or concentrations
<br />between the tested groups is rejected, and there is a statistically significant difference between the tested groups. ISDS, individual septic disposal system; °C, degrees Celsius; NA,
<br /> not applicable; µS/cm,
<br />microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; <, less than; NTU, nephelometric turbidity units; µg/L, micrograms per liter; E, estimated; N, nitrogen;
<br /> nitrate is nitrate plus
<br />nitrite; P, phosphorus; C, carbon; col/100 mL, colonies per 100 milliliters; pCi/L, picocuries per liter]
<br />
<br />Field properties, constituents,
<br />
<br />and reporting units
<br />Alluvial
<br />
<br />median,
<br />(n) Aquifer
<br />Troubl.
<br />
<br />Fm.
<br />median,
<br />
<br />
<br />-value
<br />
<br />Urban
<br />median,
<br />(n) Land use
<br />
<br />Nonurban
<br />median,
<br />(n)
<br />
<br />
<br />-value Septic disposal
<br />
<br />ISDS Non-ISDS
<br />median, median,
<br />(n) (n)
<br />
<br />
<br />-value
<br />Temperature (°C) 6.6, (39) 7.3, (24) 0.024 6.6, (38) 8.0, (32) NA 6.7, (31) 7.3, (39) NA
<br />Specific conductance (µS/cm) 256, (39) 256, (24) 0.343 258, (38) 260, (32) 0.981 260, (31) 256, (39) 0.244
<br />Dissolved oxygen (mg/L) 1.9, (39) 4.8, (24) <0.001 1.0, (38) 4.6, (32) <0.001 4.3, (31) 3.4, (39) 0.892
<br />pH (standard units) 7.3, (39) 7.8, (24) 0.048 7.2, (38) 7.9, (32) <0.001 7.6, (31) 7.5, (39) 0.385
<br />Turbidity (NTU) 0.3(38) 0.2(24) 0.016 0.3, (37) 0.3, (32) 0.732 0.3, (31) 0.22, (38) 0.285
<br />Dissolved solids (mg/L) 168, (38) 158, (22) 0.342 168, (37) 160, (30) 0.668 162, (31) 166, (36) 0.349
<br />Chloride (mg/L) 4.5, (39) 1.5, (24) 0.002 4.6, (38) 1.5, (32) <0.001 4.8, (31) 1.8, (39) 0.021
<br />Magnesium (mg/L) 4.39, (39) 3.41, (24) 0.005 4.40, (38) 2.10, (32) <0.001 3.53, (31) 2.44, (39) <0.001
<br />Sulfate (mg/L) 4.5, (38) 2.7, (22) <0.001 4.0, (37) 2.5, (30) <0.001 3.1, (31) 2.7, (36) 0.004
<br />Iron (µg/L) <10 (39) <10, (24) 0.006 <10, (38) <10, (32) 0.075 <10, (31) <10, (39) NA
<br />Manganese (pg/L) <4.0, (39) <3.0, (24) 0.008 E 6.2, (38) <3.0, (32) NA 3.9, (31) <3.0, (39) <0.001
<br />Ammonia,I as N (mg/L) 0.002, (39) <0.002, (24) 0.311 <0.002, (38) <0.002, (32) 0.761 <0.002, (31) 0.003, (39) 0.522
<br />Nitrate, as N (mg/L) 0.110, (39) 0.216, (24) 0.590 0.222, (38) 0.204, (32) 0.444 0.206, (31) 0.214, (39) 0.328
<br />Orthophosphate, as P (mg/L) 0.047, (39) 0.121, (24) <0.001 0.048, (38) 0.048, (32) 0.288 0.028, (31) 0.061, (39) <0.001
<br />Dissolved organic carbon, as C (mg/L) 1.8, (39) 0.69, (24) 0.010 1.1, (38) 0.83, (32) 0.878 0.70, (31) 1.0, (39) 0.008
<br />Total coliform bacteria (col/100 mL) <1, (37) <1, (24) 0.057 <1, (36) 1,(32) 0.983 <1, (30) <1, (38) 0.557
<br />Methylene blue active substances (mg/L) <0.02, (39) <0.02, (23) 0.006 <0.02, (38) <0.02, (31) 0.681 <0.02, (31) <0.02, (38) 0.834
<br />Radon-222, total (pCi/L) 710, (15) 1074, (12) 0.479 1096, (18) 661, (12) NA 784, (15) 752, (15) NA
<br />'Un-ionized ammonia [NH3] plus ammonium [NH4+]
<br />co
<br />co
<br />w
<br />0
<br />21
|