(continued f r o m page 186) PRECISION
Fs SCIENTIFIC
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Air Quality Instruments
Determine air quality with speed and accuracy Aeron Contlnuous No, MonltorCorrelates with ASTM D 2012. Gives continuous measure of NO, (or NO) in the atmosphere. Sensitivity is 0.02 ppm or better.
Aeron Automatic Tape Sampler/ Recorder-Complies with ASTM D 1704. Sample spots are 1 in. dia. on 2 in. centers. Automatically records O-1OO0/o light transmission.
Louis G. Williams University of Alabama University, Ala. 35486
Aeron Tape Spot Evaluator-Companion unit for the Automatic Tape Sampler. Evaluates spots at a rate of 720 spots per hqur. Indicates percent of light transmittance directly.
Don’t stop flushing yet!
DEAR SIR: Since writing the Viewpoint column on the deficiencies of the flush toilet for the January issue of ES&T (page l l ) , I have noted some reaction to the effect that it will no longer be necessary to spend large sums of money to build sewage treatment plants. If the “dry method” or some better way of keeping human wastes out of flowing water is proved successful by research, it will take many years or even decades to adopt it widely. Therefore, present efforts to construct treatment plants should continue apace. Even if such wastes are not handled by treatment plants in the future, our expanding population will generate other wastes (wash water, industrial, off-street, etc.) that will need the facilities now being constructed and planned.
Aeron Sequentlal Sarnpler-Complies with ASTM D 1605, D 1607, D 1609. Has 12 stations, each accommodating 3 tubes. Operates unattended-for up to 4 days.
Aeron Hlgh Volume Air Sampler -Complies with ASTM D 2009 and with USPHS Specifications. High capacity blower-up to 80 c.f.m. free air. Aeron Sulphur Dloxlde and DustF a l l M o n l t o r l n g Statlon-Cornplies with ASTM D 2010 (for SO,) and ASTM D 1739 (for dust-fall). Compact, stable stand assembles without tools. Also sulphation plate holders.
A s k your Precision S c i e n t i f i c Dealer for a no-obligation demonstration, complete performance data on Aeron Air Quality Instruments, or w r i t e us. Precision Scientific Company, 3737 W. Cortland St., Chibago, 111. 60647. Circle NO. 13
188 Enjironmental Science & techno log^
their effluents. ORSANCO standards do not include many of the toxic wastes from heavy industry. The Ohio River basin leads all others in the number of violations of water quality criteria for public water supplies. During the late summer and fall, effluents from heavy industry such as steel kill off beneficial communities of fish-food plankton which produce oxygen, and give rise to unwanted, but toxic-tolerant blue-green algae, similar to those in Lake Erie. These organisms have not read ORSANCO’S reports, but during the 16-week steel strike in the summer of 1959, the real water quality greatly improved because steel mill contamination ceased. ORSANCO’S predictions that the high navigation dams would result in a better control of stream flow to regulate waste assimilation did not turn out that way. Instead, toxic wastes accumulate in huge deposits in the newly formed deep pools and destroy many of the beneficial uses of the river. These ooze deposits use oxygen, produce unwanted treatment expense for water treatment plants, impart taste and odor, and impair recreational use of the river.
Harold H. Leich 5606 Vernon P1. Bethesda, M d . 20034 on Readers’ Service Card
