Contaminant Transport in Two Central Missouri Karst Recharge Areas

Abstract

Karst watersheds with significant losing streams represent a particularly vulnerable setting for groundwater contamination because of the direct connection to surface water. Because of the existing agricultural land-use and future likelihood of urbanization, two losing-stream karst basins were chosen for intensive monitoring in Boone County, Missouri: Hunters Cave and Devils Icebox. Both caves were formed in Burlington Limestone and have similar recharge areas (33 to 34 km 2 ) and land uses. Year-round monitoring was conducted from April 1999 through March 2002 to characterize the water quality of the main cave streams relative to herbicide, nutrient, and sediment contamination. Water sampling entailed grab samples at regular intervals and runoff-event samples collected using automated sampling equipment. 21 at Hunters Cave. Herbicides or their metabolites were detected in more than 80% of the samples from both cave streams, and herbicide concentrations and areal loss rates were generally similar between the sites. Overall, the greater loads and mass flux of contaminants in the Devils Icebox recharge area compared to Hunters Cave was a result of both greater stream discharge and the occurrence of more cropped fields (94%) on claypan soils with high runoff potential. These claypan soils are known to be especially problematic with respect to surface transport of contaminants. Prevailing land use has significantly degraded the water quality in both recharge areas, but a watershed plan has been developed for the Bonne Femme watershed, which encompasses these two recharge areas. With the baseline data collected in this study, the impact of changing land uses and the implementation of management practices or new ordinances designed to improve water quality can be documented.

Groundwater quality in selected caves in Ravni kotari (Croatia)

“…In general, everything from fertilizers, pesticides, metals, bacteria, petroleum hydrocarbons, and chlorinated solvents to exotic synthetic organic compounds and pharmaceuticals have been reported to contaminate cave waters (Lerch, 2011). Main sources of cave water pollutions are human activities which can cause disruption in the chemical balance of the groundwater or increase in the Uvod Izrazita heterogenost krša koja se odražava u složenim hidrološkim i hidrogeološkim značajkama posljedica je njegovih geoloških i geomorfoloških obilježja.…”

“…Općenito, u spiljskim su vodama zabilježene brojne vrste zagađivača, od gnojiva, pesticida, metala, bakterija, naftnih ugljikovodika i kloriranih otapala do egzotičnih sintetskih organskih spojeva i lijekova (Lerch, 2011). Naime, ljudske djelatnosti glavni su izvor zagađenja spiljskih voda, što može dovesti do poremećaja u kemijskom concentration of the microorganisms, particularly bacteria.…”

“…Naime, ljudske djelatnosti glavni su izvor zagađenja spiljskih voda, što može dovesti do poremećaja u kemijskom concentration of the microorganisms, particularly bacteria. The most frequent sources of contamination include waste dumping activities (point sources) or agricultural and farming activities (diffuse sources) which include possible contaminants such as nutrients added as fertilizers (especially sulphate, nitrogen, phosphorus and potassium), pesticides applied to the crops, and bacteria ( Jimenez-Sanchez et al, 2008;Lerch, 2011).…”

“…Frequent monitoring is particularly importsastavu podzemne vode te do povećanja koncentracije mikroorganizama u vodi, posebice bakterija. Najčešći su izvori zagađenja odlagališta otpada (točkasti izvori) te poljoprivredne djelatnosti (raspršni/difuzni izvori) unutar kojih se kao potencijalni zagađivači ističu nutrijenti koji se upotrebljavaju kao gnojiva (posebice sulfati, dušik, fosfor i kalij), pesticidi koji se primjenjuju na usjevima te bakterije ( Jimenez-Sanchez i dr., 2008;Lerch, 2011).…”

“…To nameće potrebu stalnog nadziranja (monitoringa), ant in assessment of concentration of contaminants with seasonal inputs and limited environmental persistence. Such data is necessary to determine the potential toxicity of contaminants in karst ecosystems (Lerch, 2011).…”