Document Type

Technical Report

Publication Date

7-1-2009

Keywords

water quality, rivers and streams, Arkansas

Abstract

The Arkansas Water Resources Center monitored water quality at Ballard Creek at the Washington County Road 76 Bridge in northwest Arkansas during base flow and storm events from July 1, 2008 through June 30, 2009. Water samples were collected manually or with an auto-sampler and analyzed for nitrate-nitrogen, ammonia-nitrogen, total nitrogen, total phosphorus, soluble reactive phosphorus, sulfate, chloride and total suspended solids. Instantaneous stage and discharge were recorded at the site; total annual discharge was 55,800,000 m³ , with 27% attributed to base flow and 73% attributed to storm flow. Loads were estimated using the mid-interval integration approach using continuous discharge (i.e., 30 min intervals) and measured concentrations as applied to sampling intervals; the incremental loads were then summed to get annual loads for the 2008 calendar year. The constituent loads and annual flow-weighted concentrations are summarized in the table below, using data collected through this study (July through December 2008) plus data from the prior study (January through June 2008).

Report Number

MSC353

Page

9

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