2015-01-14_REPORT - C1981035 (4)

Home Browse Search

King I — Wiltze Well — Sampled since 2/1/1982. This well demonstrates a significant fall in the water table servicing this well, suggesting reduced annual rainfall in the Hay Gulch drainage. This is mirrored by an increase in Field EC, however the TDS, total Sulfate and Manganese levels are trending downward, suggesting a change in the ionic profile of the water entering the Wiltze monitoring well. Other major anions, cations and pH trends all remain unchanged. CDS is unable to provide an interpretation of this collection of trends, other than the introduction of a water source with lower levels of Manganese and sulfate. King II Up- gradient well — Sampled since 1/1/2005. The most evident trend is the lowering of the water table over the nearly ten year sampling period. The average depth to water dropped about twenty -five inches. This trend is also found in the King I — Wiltze Well, which is located about one mile to the east in the floor of Hay Gulch. The chemistry of this well has varied considerably during its almost ten years of sampling. For example, the levels of Magnesium and Manganese have increased about ten -fold, while the TDS remained almost level. Slight reductions are seen in Iron [from about 0.15 mg /L in 2005 down to non - detect in 2013 -2014] and Sodium [from about 322 mg /L to about 118 mg /L, a 50% reduction] in a bit less than ten years. The reduction of surface water from rain and irrigation will allow other deeper sources of water, with higher levels of cations [hardness], to produce selected increased levels while the overall TDS is reduced. King II Down - gradient well — Samples since 1/1/2005. The single most striking observation seen in this monitoring well is the extreme variability of water depth. In four dry periods [2006 through 2008] the water level dropped to 100 inches or lower. These dry years were offset by three very wet years when the water level was very near the surface [2005 at 2 inches; 2008 at 22 inches and 2010 at 12 in inches]. When compared to the up- gradient well, where the trend of water level is downward and significant, this down - gradient well water level has a near level trend, even with its high degree of variability. Even with the down - gradient well's high degree of water depth variability all major anions and cations were almost unchanged. [the slight decrease shown may not be statistically valid]. A single outlier is the reduction in Manganese which has a valid downward trend from around 0.2 mg /L to almost non - detectable [0.005 mg /L to ND]. King II Hay Gulch Ditch — Sampled since 1/1/2005. As seen in other monitoring wells all tested parameters exhibit high degrees of variability from quarter to quarter and from year to year. When trend analysis is performed, the trends are essentially flat, for all monitored anions and cations, across the nearly ten year monitoring period. The notable exception is sulfate which demonstrated a significant reduction from about 90 mg /L to below 60 mg /L, suggesting a reduction in leached sulfate from the sulfate laden soils [derived from shales and mudstones] that line the Hay Gulch alluvium. The variability of Hay Gulch Ditch measured parameters strongly resembles the dry years seen in the monitoring wells, suggesting the ditch also receives rain leachate in addition to the water it receives from the La Plata River.