WSP01544

• File Number: 8170
• Description: Arkansas Basin Water Quality Issues
• State: CO
• Basin: Arkansas
• Water Division: 2
• Date: 1/1/1996
• Author: Bradford Austin
• Title: Report to the Commissioner of Agriculture - Colorado Department of Agriculture - Ground Water Monitoring Activities - Arkansas River Valley Alluvial Aquifer - 1994-1995
• Water Supply Pro - Doc Type: Report/Study

I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

0284
INTRODUCTION

The Water Quality Control Division CWQCD) of the Colorado Department of Public
Health and Environment (CDPHE) has responsibility under the Agricultural Chemicals and
Ground Water Protection Program (SB 90-126) to conduct monitoring for the presence of
commercial fertilizers and pesticides in ground water. The Agricultural Chemicals Program
has been established to provide current, scientifically valid, ground water quality data to the
Commissioner of Agriculture. Prior to passage of SB 90-]26, a lack of data had prevented an
accurate assessment of impacts to groundwater quality from agricultural operations. This
program will assist the Commissioner of Agriculture in detennining to what extent agricultural
operations are impacting ground water quality. The program also assists the Commissioner in
identifying those aquifers that are vulnerable to contamination. The philosophy adopted is to
protect ground water and the environment from impairment or degradation due to the
improper use of agricultural chemicals, while allowing for their proper and correct use.

This report has been prepared for the Commissioner of Agriculture to provide a
summary of the monitoring work completed in the Arkansas River Valley alluvial aquifer in
1994 and ]995. This report details the monitoring work required by SB 90-126, including an
evaluation of possible impacts to ground water quality from current and past use of
agricultural chemicals in the Arkansas Valley.

The scope of this project involves the collection and laboratory analysis of ground
water samples. This monitoring program was planned to meet the objectives necessary for a
preliminary detennination of the existence of agricultural chemicals in the ground water in a
safe, cost effective, and timely manner.

The ground water quality sampling program is intended to fuLfill the following
objectives:

I. Detennine if agricultural chemicals are present in the ground water.
2. Provide data to assist the Commissioner of Agriculture in the identification of
potential agricultural management areas.

The factors considered in the choice ofthe Arkansas River Valley as a study area are:

I. The Arkansas Valley is a major agricultural area of Colorado.
2. The ground water in the alluvial aquifer within this area is shallow in depth.
3. The area is heavily irrigated by both surface water diversions and ground water
pumpage.
4. The soil types are conducive to leaching.
5. The alluvial and deeper bedrock aquifers are utilized for irrigation and domestic
water supplies throughout the basin.
6. Colorado State University Extension and USDA Natural Resource Conservation
Service have chosen the Arkansas Valley as the site for various water quality
demonstration projects.

1