COMMUNICATIONS
Organic Content of Southwest and Pacific Coast Municipal Waters Kurt H. Nelson and Ihor Lysyj Research Division, Rocketdyne, a Division of North American Rockwell, Corp., Canoga Park, Calif.
Water samples from municipal supplies in some Southwest and Pacific Coast communities were analyzed for organic content by a pyrographic technique. The organic content averaged 0.9 mg. of carbon per liter for the supplies from underground sources. Municipal supplies obtained from surface sources in desert and semiarid regions had organic contents from 1.1 to 2.7 mg. of carbon per liter. Those procured from surface waters in the northern Pacific Coast, which has abundant rainfall and heavily forested drainage basins, had organic contents from 3.7 to 7.7 mg. of carbon per liter. .
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study was undertaken to accumulate data on the organic content of water available to consumers through municipal distribution systems, and to assess three factors which could affect the organic content-i.e., source, climates, and treatment. The only information found in rhe literature H B S that the carbon chloroform extract (CCE) should not exceed 200 pg. per liter in municipal waters, clean surface and ground waters usually contain only 25 to 50 pg. per liter of CCE, and highly colored waters may exceed this level (American Public Health Association, 1965). For this study, municipal supplies from communities in the Southwest and Pacific Coast regions of the United States were used. In these regions, the climate ranges from desert to rain forest with the accompanying changes in vegetation. The sources are both surface and underground waters, and the treatment before delivery to the consumer varies from only chlorination t o complex processes using coagulation, filtration, and chlorination (U.S. Public Health Service, 1964). Experimental
Apparatus. A detailed description of the apparatus used for the pyrographic measurement of the organic content of water is presented by Lysyj and Nelson (1967). The apparatus consists of a steam generator and a sample injection system connected t o a pyrolysis chamber contained in a microcombustion furnace. This chamber is in turn connected to a
flow stabilization column of glass beads installed in a gas chromatograph which is equipped with a hydrogen flame ionization detector. A 1-mv. recorder with a 2-inch-perminute chart speed completes the apparatus. Procedure. Sample bottles cleaned with hot nitric acid containing 10% sulfuric acid were used for sample collection. The water samples were collected from the tap in each community listed in Tables I and 11. In the analysis, a 0.25-ml. aliquot of a water sample was injected into the pyrolysis chamber a t 6-minute intervals. The fragments, which were produced by the pyrolysis of the organic matter present in the water, were transported by the steam carrier gas through the flow stabilization column to the detector. Because no separation is achieved on this column, the total organic fragments were measured by the flame ionization detector. The organic content of the water sample was calculated from the average peak area. Materials representative of the major organic classes present in the water were used for calib1,ation.
Table I. Organic Content of Municipal Waters from Ground Sources Organic Content, Rlg.
CarbonjlAer
IIunicipality Arizona Flagstaff Grand Canyon Kingman California Carlsbad Paso Robles Salinas San Juan Capistrano Santa Ana Santa Barbara Thousand Oaks New Mexico Albuquerque Grants
0.7 0.8 I .6
0.8 0.9 0.9 1.5
0.7 1.o 0.9
0.9 0.7
Volume 2, Number 1, January 1968 61
Table 11. Organic Matter in Waters Distributed by Municipalities Utilizing Surface Sources Organic Content, RIg.
Municipality Arizona Williams California Alameda Del Mar
Los Angeles Redding San Diego San Luis Obispo San Mateo Santa Rosa Santee Ventura Nevada Las Vegas Reno New Mexico Santa Fe Oregon Eugene Gold Beach Medford Portland Seal Rock Tillamook
Source
Carbon/ Liter
Surface
1.3
Reservoir Cottonwood Creek and Otay River Owens River Sacramento River Cottonwood Creek and Otay River Salinas River and Creek Lakes and Streams Russian River Cuyamaca Lake Ventura River
2.1 1.1 2.7 4.8 1.4 1.3 1.1 3.7 1.6 2.5
Lake Mead Truckee River and Hunter Creek
1.3 1.6
Santa Fe River
1.3
McKenzie River Rogue River Big Butte Springs and Bear Creek Bull Run Lake and Bull Run River Deer Creek Killiam and Fawcett Creeks
7.7 6.3 4.7 7.7 3.9 6.4
Results and Discussion
The organic contents of the municipal water supplies originating from ground waters are presented in Table I. These municipalities are located in southern California and the Southwest, and all use wells as the source of water with the exception of the Grand Canyon which uses an infiltration gallery. In general, these waters, if treated, are only chlorinated before use. Table I shows these municipal water supplies averaged 0.9 mg. of carbon per liter with a range of 0.7 to 1.6 mg. of carbon per liter, which indicates that a water supply obtained from underground sources in a region with a low annual rainfall and sparse vegetation would have an organic content of about 1 mg. of carbon per liter. N o data on organic contents are available for well waters from northern California or Oregon where the precipitation is greater and the land is heavily forested. Organic contents are presented in Table I1 for the supplies in municipalities utilizing surface waters as a source. The treatment of these waters before distribution to the consumer varies from only chlorination to a complete purification treatment including coagulation and filtration. There was no correlation 62 Environmental Science and Technology
between the amount of organic matter and the treatment given the water. Municipal supplies obtained from surface sources generally have much higher organic contents than those procured underground (Table 11). The municipalities in Oregon and northern California have waters with high organic contents as indicated by values ranging from 3.7 mg. of carbon per liter for Santa Rosa, Calif., to 7.7 mg. of carbon per liter for Portland and Eugene, Ore. These high values are the result of climate and vegetation. The northern Pacific Coast region has a high rainfall, and the drainage basins are heavily forested which contributes very significantly to the organic content of the water. For example, the source of water for Portland is a protected, uninhabited mountainous watershed on the Cascade mountains and is densely covered with trees and other vegetation. The organic matter in this municipal water is derived solely from vegetation with none originating from pollution. In contrast, municipal waters procured from streams in the desert or semiarid Southwest region with sparse vegetation have a much lower organic content. The level of organics in the streams approaches that of the ground waters in the area as indicated by a comparison of the two nearby municipalities of Santa Fe and Albuquerqhe. The organic content of Santa Fe water obtained from the Santa Fe River was 1.3 mg. of carbon per liter and that of Albuquerque water from wells was 0.9 mg. of carbon per liter. Similarly, waters procured from ground and surface sources in the adjacent communities of Flagstaff and Williams had organic contents of 0.7 and 1.3 mg. of carbon per liter, respectively. The organic contents of all these municipal waters are in the range of values for natural waters reported by other investigators using various analytical techniques. In a study of 529 lakes, the organic carbon content ranged from 1.2 to 28.5 rng. of carbon per liter with a mean of 7.7 mg. of carbon per liter (Birge and Juday, 1934). Of these lakes, 327 had an organic content between 3 and 10 mg. of carbon per liter. Other investigators found lake and reservoir waters contained from 1.7 to 15.2 mg. of carbon per liter (Datsko, Vasil’eva, et a/., 1964; Krylova and Skopintsev, 1959; Votintsev, 1955). River waters had from 2.0 to 34.8 mg. of carbon per liter depending on the season (Alekin and Brozhnikova, 1960; Datsko and Vasil’eva, 1961; Krylova and Skopintsev, 1959). Literature Cited
Alekin, 0. A., Brozhnikova, L. V., Socrem. Osudki Morei i Okeanou. Akad. Nauk SSSR, Komis. po Osado Porodam pri Otd. CeoI.-Geogr. Nauk. Tr. Soueshch. 1%0, p. 28. American Public Health Association, “Standard Methods for the Examination of Water and Wastewater,” 12th ed., pp. 217-18, AWWA, APHA, WPCF, New York, 1965. Birge, E. A., Juday, C., Ecol. Monographs 4 (4), 440 (1934). Datsko, V. G., Vasil‘eva, V. L., Gidrokhim. Materialy 33, 28, 34 (1961). Datsko, V. G., Vasil’eva, V. L., Romenskaya, N. N., Ivleva, I. N., Semenov, A. D., Gidrokhim. Materialy 37, 63 (1964). Krylova, L. P., Skopintsev, B. A., Gidrokhim. Materia!,, 28, 28 (1959). Lysyj, I., Nelson, K. H., J . Gas Chromatog., December 1967. U. S. Public Health Service, “Municipal Water Facilities,” U.S.P.H.S. Pub. No. 775 (revised), 7, 32-39; 9, 7-18, 28, 33,53,65-84,105,114-24 (1964). Votintsev, K. K., Dokl. Akad. Nauk. SSSR 101, 359 (1955). Received for review August 18, 1967. Accepted December I , 1967. Work was conducted under Contract 14-01-0001-332 from the Office of Saline Water.
