Armored stanchion cattle water access effects on E. coli, suspended sediment, and nutrient loading to spring creeks

Abstract

Livestock grazing activities contribute to impairment of 5,200 miles of Montana streams. Implementation of most water quality improvement efforts addressing this issue is voluntary. Thus, it is important to present land owners with simple, cost effective approaches to mitigate water quality impairment. An armored stanchion (AS) water access was designed, implemented, and tested on Thompson and Story Creeks near Belgrade, MT. Riparian fencing was constructed to allow access at a water gap where the AS was constructed. The AS allows animals to access spring creek water to drink but does not allow them to enter the stream. An AS was constructed adjacent to a traditional (TRAD) water access on each stream for comparison. Water quality impairment was quantified downstream of each access with and without animals actively using the accesses. Instantaneous loads of E. coli, suspended sediment concentration (SSC), total Kjeldahl nitrogen (TKN), nitrate (NO3), total phosphorus (TP), and orthophosphate (PO4) were evaluated using Kruskal Wallis procedures. Contaminant loading from the AS access was not significantly greater than loading from the control with or without animals present. The Story Site did not consistently produce significant differences for the TRAD access with animals present versus absent under the different analysis approaches employed. Results at the Thompson Site produced significant differences for E. coli, TKN, and TP for the TRAD access when animals were present versus absent from the access. Estimates were made of percentage of time cattle occupied the Thompson TRAD access. These estimates facilitated calculation of daily loads attributed to animals actively using the access. For E. coli the load was 6.0 E9 CFU per day, 425.9 g per day for TKN, and 53.1 g per day for TP. These results indicate the AS access can reduce water quality impacts from cattle, compared to traditional access methods.