Automated methods for assessing water quality come of age

Abstract

The increase in the number of water samples tested at alt regulatory agency levels over the past five years was enormous. Not only has the quantity of samples grown dramatically, but the number of, parameters being measured has increased as well. Since the passage of the Federal Water Pollution Control Act Amendments of 1972, many state agencies have been empowered to perform this work on a greatly expanded level. Although not all states have as yet been empowered with this responsibility, it is only a matter of time and the acquisition of technical expertise before they will be so empowered.This growth in the amount of testing is continuing. Passage of the Safe Drinking Water Act (1974), and continuing National Pollutant Discharge Elimination System (NPDES) permit legislation will undoubtedly create even greater demands on workloads that are already at a significant level.Manual analytical technology cannot possibly cope with this burgeoning workload. Just considering space and manpower requirements alone, without considering data handling requirements and the budgetary squeeze with which many agencies are presently being confronted, makes this quite evident. The availability of automated analytical instrumentation and technology has enabled the regulatory agencies, as well as laboratories in the private sector, to handle these everincreasing workloads, without significant increases in space and personnel. According to EPA's Dr. Mark J. Carter in Chicago, "We would have had to make tremendous increases in numbers of personnel had we continued to handle our analytical workload using manual procedures."Many automated wet chemical methods are listed in the 1974 edition of EPA's Manual of Methods for Chemical Analysis of Water and Wastes, which contains the chemical analytical procedures used in EPA laboratories for the examination of ground and surface waters, domestic and industrial waste effluents and treatment process samples. To quote from the introduction to the Manual ". . . method selection was based on the following criteria:1. The method should measure the desired property or constituent with precision, accuracy, and specificity sufficient to meet the data needs of EPA, in the presence of the interfering materiafs encountered in water and waste samples.2. The procedure should utilize the equipment and skills available in modem water pollution control laboratories.

Water analysis

“…Krawczyk and Allen (12F) studied the adsorption of orthophosphate on borosilicate, citrate of magnesia, polyethylene, and polyvinyl bottles in both a distilled water and seawater matrix. There are no problems with glass bottles at low orthophosphate concentrations in distilled water up to 7 days, but they must first be acid washed. In seawater, losses of orthophosphate were noted after 16 days in polyethylene.…”

“…DuCros and Salpeter (7) discussed automated methods for assessing water quality. Greater concern for water quality has caused significant increases in the analytical workloads of laboratories.…”