Chemical composition of water in the Putah Creek basin

Abstract does not appear. First page follows.

Introduction

Concurrently with the 1931-1932 hydrologic investigation of Putah Creek basin, reported by Huberty and Johnston in the accompanying paper ⁽³⁾,4 studies of water quality were being made.5 The purpose of the study was to determine, from analytical data, the classification of waters of the area as to their chemical composition; the seasonal variation in the character and amount of dissolved salts; and to determine the boron content of the waters, since this element is highly toxic to most plants when present even in minute quantities ⁽¹⁾,⁽²⁾,⁽⁴⁾.

Methods of Procedure

Samples were obtained from the pump discharge of wells penetrating water-bearing formations of various depths. Figure 1 shows the locations of the wells, from which water samples were collected in glassstoppered bottles for analysis. From a small number of wells, perforated at only one water-bearing stratum, water samples were collected at intervals of from one day to one week to determine the seasonal variation in salt content.

Water samples of from 2 to 4 liters, collected in glass-stoppered bottles were placed in wooden containers and immediately taken to the laboratory where determinations were made for pH, bicarbonate, carbon dioxide, and nitrate. Later analyses were made for calcium, magnesium, sodium, potassium, iron, carbonate, sulfate, chloride, phosphate, nitrate, silicon, aluminum, and boron. The total solids were determined at 105° c.

Results of the Analyses

The results of the determinations of bicarbonate and chloride ions on samples collected to show seasonal changes in the dissolved salt content are recorded in table 1. Table 2 contains the analyses of well waters obtained within Putah Creek lower basin, and the results are reported in parts per million. The pH values reported. in the second column were obtained soon after the samples reached the laboratory. For the convenience of those not accustomed to interpreting water analysis in parts per million, table 3 is introduced.