priaritypau~ts What are they? Toxic chemicals. How many are there? 129. Complying with a 1976 court settlement, the U.S. Environment Protection Agency is spending about $60 million to obtain the necessary data f o r forthcoming regulations that are the beginning of a better way to monitor industrial wastewater discharges. Next month’s authors present a cost-effective method to analyze f o r these pollutants Larry H. Keith Radian Corporation Austin, Texas 78766 William A. Telliard U S .EPA Washington, D.C. 20460
One objective of this article is to relate the historical origins of EPA’s Priority Pollutants and the development of the “Priority Pollutant Protocol.” Most people are unaware of the difficulties involved in providing methods for the necessary analytical support for these pollutants. A second objective is to summarize the status of the current analytical procedures in their present and still-developing forms. A June 7, 1978, court settlement involving the EPA and several environmentally concerned plaintiffs (Natural Resources Defense Council, Inc.; Environmental Defense Fund, Inc.; Businessmen for the Public I n terest, Inc.; National Audubon Society, Inc.; and Citizens for a Better Environment) has commonly become known as the “EPA Consent Decree.” These groups brought suits against the EPA for failing to implement portions of the Federal Water Pollution Control Act (P.L. 92-500). One result of this suit required EPA to publish a list of toxic pollutants for which technology-based effluent limitations and guidelines would be required ( E S &T , February 1978, p 154). The Consent Decree dictates that, ‘‘. . . the (EPA) Administrator shall develop and promulgate regulations which shall establish and require achievement at the earliest possible 416
Environmental Science & Technology
oint-source categories
Is and converted
d wood chemicals
tronic components
These new dates for promulgationare awaiting approval by
0013-936X/79/0913-0416$01,00/0
@ 1979 American Chemical Society
time, but in no case later than June 30, 1983, of effluent limitations and guidelines for classes and categories of point sources which shall require application of the best available technology (BAT) economically achievable for such category or class . . .” The Consent Decree also requires new source performance standards and pretreatment standards for 21 industrial categories (Table I ) . In addition, EPA has decided to review public owned treatment works (POTWs) as a separate category. The original Consent Decree contained a strict scheduling of contracts to be issued and dates for the required regulations to be promulgated (Table I ) . T h e schedule originally gave contractors only 15 months to complete their analyses and evaluations. New dates, which will give EPA more time, a r e awaiting approval by the U S . District Court. Another component of the Consent Decree was a list of 65 compounds and classes of compounds (Table 2). A set
of technology-based regulations are to be established for the control of the “65 pollutants” in all 21 point-source industrial categories. This list eventually formed the Toxic Pollutant List included in P.L. 92-500 under Part 307 (a) which concerns toxic materials. rdta,.ifion
for
Environmental and analytical chemistry play significant roles in obtaining data upon which these regulations are being based, but there were some details that were omitted: Minimum detection levels were not specified. The list of 65 compounds and classes of compounds could include thousands of pollutants if all compounds in each of the classes and all organometallic compounds were considered.
Standard methods for collecting and preserving the organic samples were unavailable. Standard methods for analyzing organics in complex wastewaters were unavailable. Nevertheless, contracts were let as mandated, samples were taken and analyses were begun. Concurrent with these activities, EPA chemists were trying to resolve some of the analytical problems caused by the Toxic Pollutant List. At an informal meeting in Kansas City in late October 1976, we proposed that the initial (Screening Phase) analyses for the organic pollutants be conducted by gas chromatography-mass spectrometry (GCMS). G C - M S was the only available technique that could identify a wide variety of compounds in many different matrices and in the presence of interfering compounds. Previous experience with natural and drinking water samples had shown that many compounds in water could be identified and semi-quantified at the 1 part per
Volume 13,Number 4, April 1979
417
billion (ppb) level using computer controlled GC-MS. Therefore, 10 ppb was suggested as a reasonable level to analyze for in industrial effluents. Analytical minimum detection levels for many pesticides already existed in the Federal Register, so it was suggested that those standard methods and detection levels be used to analyze for pesticides and polychlorinated biphenyls (PCBs). However, a problem still existed with the-concept of analyzing for so many classes of organic compounds in the Toxic Pollutant List. The challenge of chemical analysis of a sample for literally thousands of components is staggering-especially when these components may be at part per billion levels in a complex sample matrix. The expenditure of resources in government as well as private laboratories would be overwhelming if analyses were attempted for all possi-
ble chemicals on the original list of compounds and compound classes. In order for contractors to be able to submit costs for conducting analyses, they had to at least have a finite list of compounds to be analyzed for. Therefore, a second meeting was held a few weeks later in Atlanta to resolve the Consent Decree Toxic Pollutant List into one that was contractually and analytically manageable. In addressing the 13 metals on the Toxic Pollutants List the term, “. . . and their compounds,” was interpreted to mean “total metals,” which would include both inorganic and organometallic compounds. The standard method for analysis of total cyanides was selected and asbestos methodology was deferred until later. This left a list of 50 categories of organic pollutants. Not counting PCBs, toxaphene, and chlordane, there were 18 groups of
organic pollutants, each containing 2 to 50 compounds. T o resolve these groups into a list with finite proportions required decisions that addressed the Consent Decree. Four criteria were employed to prioritize and select specific representative compounds for each group. This provided the required specificity necessary for developing analytical methods and for contract management without excluding other compounds in those classes that may be of future concern. All compounds specifically named in the Toxic Pollutant List (Table 2) were automatically included. The availability of chemical standards for verification and quantification was considered mandatory. Therefore, every representative compound added had to be listed in at least one chemical supply catalog.
TABLE 3
e relative frequency of these rnateriak
1 are purgeable organic8
418
Environmental Science & Technology
Frequency of occurrence of the representative compound in water was an important consideration. All compounds except those named in the Toxic Pollutant List were considered if they were found with a frequency of 25% of the total known listings for that class of compounds. Chemical production data were used as a guide for prioritizing choices when they were available. A draft manuscript of a n EPA report listing all known organic pollutants (other than pesticides) identified worldwide in water through June 1976, was used for the criterion of whether a compound was a recognized water pollutant (Shackelford and Keith, Frequency of Organic Compounds Identified in Water, EPA600/476-062). Ten organic chemical catalogs were searched to determine whether chemical standards were
Percent Of
sampksa
commercially available. Finally, Stanford Research Institute’s “1976 Directory of Chemical Producers, USA,” and Radian Corporation’s “Organic Chemical Producers’ Data Base Program” were used to gather data concerning manufacture of various candidate compounds. A list of 123 materials was finally compiled and submitted to the environmental plaintiffs in the Consent Decree. At their request, five additional Aroclors and di-n-octyl phthalate were added to raise the total to 129 (counting the Aroclor mixtures, chlordane, toxaphene, and asbestos each as a Priority Pollutant). Table 3 summarizes this list and also indicates the relative frequency with which these compounds are being found in industrial wastewaters. Once the Priority Pollutants were defined as a finite list of materials it
Number ot imdustrlal catagorlesb
was possible to develop a sampling and analysis strategy: metals asbestos total cyanides pesticides compounds extracted under acidic conditions 0 compounds extracted under alkaline conditions neutral extractable compounds total phenols purgeable compounds Because of their availability, i t was decided to use standard pesticide methodologies for the analysis of pesticides and their metabolites. This usually involves extraction, Florisil column cleanup of the concentrated extract and gas chromatographic
Percent of rampleea
Number of industrial categories*
0.1 0.1 1.4
1 2 6
4.5 4.2 8.5
12 14 13
Acenaphthylene Acenaphthene Butyl benzyl phthalate
26.1 2.3 2.2 1.6 1.1 6.9
25 11 9 6 6 18
11 are acid extractable organic compounds Phenol 1.9 2-Nitrophenol 2.3 4-Nitrophenol 3.3 2,eDinitrophenol 4.6 43-Dinilro-o-cresol 5.2 Pentachlorophenol
0.3 0.4 0.2 0.6 0.2 0.5 0.5 0.1 0.04 0.1 0.2
3 4 2 4 6 4 3 5 3 1 2 2
26 are pesticldes/PCB’s a-Endosulfan 0.3 0.1 @-Endosulfan 0.2 Endosulfan sulfate CY-BHC 0.2 @-BHC 0.6 &BHC 0.5 y-BHC 0.9 Aldrin 0.8 Dieldrin 0.6 4,4’-DDE 0.6 4,4‘-DDD 0.5 4,4’-DDT
0.2 0.2
3 2
Endrin Endrin aldehyde
18.1 19.9 14.1 30.7 53.7 55.5 43.8
20 19 18 25 28 28 27
Antimony Arsenic Beryllium Cadmium Chromium Copper Lead
33.4
19
Total cyanides
0.8
The priority pollutants can be divided into nine groups
8 10 12 12 15
3 1 4 2 2 1 2 3 2 3 1
-
N-nitrosodimethy lamine N-Nitrosodi-n-propylamine bis(2-Chloroisopropyl)ether
pChlorc- mcresol 2-Chlorophenol 2.4-Dichlorophenol 2,4,6-TrichlorophenoI 2,4-Dimethylphenol
Heptachlor Heptachlor epoxide Chlordane Toxaphene Aroclor 1016 Aroclor 1221 Aroclor 1232 Aroclor 1242 Aroclor 1248 Aroclor 1254 Aroclor 1260
2,3,7,8-Tetrachlorodibenzopdioxin (TCDD)
13 are metals 16.5 34.7 18.9 22.9 19.2 54.6
20 27 21 25 19 28
Mercury Nickel Selenium Silver Thallium Zinc
Miscellaneous Not available
Not available
Asbestos (fibrous) Total phenols
a The percent of samples represents the number of time$ this compound was found in all samples in which it was analyzed for divided by the total as of 3 1 August 1978. Numbers of samples ranged from 2532 to 2998 with the average being 261 7 A totat Of 32 industrial categories and subcategories were analyzed for organics and 28 for metals as of 31 August 1978.
Volume 13, Number 4, April 1979
419
analysis, using an electron capture detector. Since there were few basic compounds, this group was combined with the neutral compounds. The acid extractable Priority Pollutants include only phenols. The remaining organic compounds, with the exception of acrolein and acrylonitrile, were readily purgeable from aqueous solutions. The latter two were analyzed by direct aqueous injection GC-MS. There are three phases of analyses involved with the Priority Pollutants. T h e initial work is referred to as the “Screening Phase.” Its objective is to define which of the Priority Pollutants are in the treated and untreated wastewaters of each of the industrial categories. The second “Verification Phase” is to determine the efficiencies of the various treatment technologies under consideration. T h e final “Monitoring Phase” will be used for compliance monitoring of state and federal discharge permits. *, three phases of e s include screening, ,ation, and monitoring. eening phase complete; ation 40 YO complete, monitoring phase yet keen initiated j
A semiquantitative analysis by
GC-MS is all that is required to achieve the objective of the Screening Phase. Three characteristic fragment ions were chosen for each compound and chromatographic methods were devised that would allow unambiguous identification of each compound (with few exceptions). Tom Bellar and Jim Lichtenberg, at EPA’s Environmental Monitoring and Support Laboratory in Cincinnati, Ohio, had been investigating a purge and trap method for analyzing very volatile organic compounds in water, and this technique was applied successfully to 29 of the Priority Pollutants. The late Ron Webb, at EPA’s Environmental Research Laboratory in Athens, Georgia, had been investigating liquid-liquid extraction and various concentration methods for isolating intermediate volatile organic compounds from water; these techniques were applied successfully to 57 of the Priority Pollutants. Eleven of the extractable compounds are phenols extracted under acidic conditions with methylene chloride, and 46 are neutral and basic compounds extracted under alkaline conditions with the same solvent. The 26 pesticides are extracted with a methylene chloride-hexane mixture, using a separate aliquot of 420
Environmental Science & Technology
Pesticide analysis, ..?fter c’< [rN(/ / o i l N ~ ol,qiin/ I i r injecied into a gas chromatograph
wastewater. The purgeablc samplc from the water and adsorbed in a requires a third aliquot of wastewater stainless steel trap packed with Tenax-GC and silica gel. At the comcollected separately. The decision was made to use con- pletion of the purging step, the gas flow ventional packed columns for all to the trap is reversed and the trap is rapidly heated to I80 “C. The organics chromatographic separations even though it was realized that capillary are thermally desorbed from the trap columns would provide superior reso- to the head of a gas chromatographic lution. Because most laboratories had column held at room temperature. had little experience with capillary When desorption is complete the columns, and since the identifications chromatographic column is temperaand quantifications were to be based ture programmed and the organic on selected characteristic ions within compounds are eluted into a coma small retention time “window,” it puter-controlled mass spectrometer was not necessary that complete where they are identified and quantichromatographic resolution of all or- fied. Initially acrolein and acrylonitrile ganic Priority Pollutants be were analyzed by direct aqueous injection, but as of September 1978, the achieved. To preclude omission of other or- EPA has authorized an optional ganic compounds potentially included analysis using the purge and trap by the classes of compounds in the technique. Toxic Pollutants List, all GC-MS data are being committed to permanent storage on magnetic tape. Likewise, the organic extracts are being sealed and stored at subzero temperatures at the Athens. Georgia. Environmental Research Laboratory. These extracts and GC-MS tapes make u p the most extensive and representative crosssection of data on organic compounds in industrial wastewaters that has ever been compiled. These will be examined further for additional compound identifications over the next several years. Water samples for the purgeable conipounds are collected in 40-mL glass vials with Teflon-lined septa. The vials are completely filled so no bubbles are present. Usually 5 mL of this sample, spiked with bromochloromethane and I ,4-dichlorobutane as internal standards. is used for the analysis, After being transferred to a glass sparging tube with a fritted-glass bottom, the sample is purged w i t h helium. The volatile organics are stripped
The Extractables. Two liters of water from a 3-day composite sample are made strongly alkaline and extracted with methylene chloride. The extracts a r e concentrated in two stages, using first a Kuderna-Danish concentrator and second a microSynder column. An internal standard of dlo-anthracene is added to the 1 .O mL concentrated extract, which contains all the “Base/Neutral Priority Pollutants.” The same 2 L of water is then made strongly acidic and reextracted with methylene chloride. Concentration and addition of the same internal standard produces the extract containing all of the “Acidic Priority Pollutants.” Injection of 2 pL of these extracts into a G C - M S provides a minimum of 40 ng of each extractable Priority Pollutant at 10 parts per billion or more i n the water and 40 ng of the internal standard. The original G C column packing for Base/ Neutrals ( 1 % SP-2250 on Supelcoport) has been replaced by 1 % SP2250 DB on Supelcoport. The original G C column for the Acid Extractables (Tenax-GC) has been replaced by 1% SP-1240 DA on Supelcoport. These new column packings provide better chromatographic results than the original packings, and the EPA has purchased large lots which it provides to all of its regional and contract laboratories in a n effort to make all analyses as uniform as possible. For pesticide analyses a separate liter of water from the composite sample is extracted with hexane/ methylene chloride, concentrated to 10 mL and the extract is fractionated on a Florisil column. Analysis of the pesticide extracts requires G C columns used for standard pesticides work under isothermal conditions and an clectron capture detector. Pesticides identified using these methods must be confirmed by GC-MS. An automated software program comple t e!d identified the pres,=nce or absence of the organic priority pollutants ;and quantifies them wiithin minutes
Computer-controlled GC-MS analyses lend themselves to computer-assisted analyses and several laboratories are developing various degrees of automated analyses. Radian Corporation, for example, has an automated software program that analyzes the mass spectral data and, on the basis of fragment ions and their correct ratios, relative retention times, ion intensities relative to the internal standard and response factors, completely
Elemental analysis. ‘Technicians are u Ying 1.entc.d A A units for the presence of metals
identifies the presence or absence of the organic Priority Pollutants and quantifies them w i t h i n minutes. Manual processing takes 3 to 4 hours to achieve the same results. Statistical analyses of more than 4500 data points revealed only 0.13% false-positive and 0.04% false-negative computer identifications at a concentration level greater than I O ppb. Automated G C - M S analyses of the Priority Pollutants, while not yet approved methods, are obviously the coming trend. The EPA intends to evaluate the performance of the most promising of these computer programs in the near future. Not only are computerized analyses most cost effective, they do not use highly trained people to do what will eventually become routine analyses. Furthermore, the computer does not tire of performing tedious repetitive functions over long periods of time and is less likely to make errors than a human. The Metals. All of the metals analyses performed during the Screening Phase and a large number of metals analyses from the Verification Phase are being analyzed by the EPA Central Regional Laboratory in Chicago. The primary reason for utilizing one laboratory for metals analysis was that the Chicago Regional Laboratory had an inductively-coupled plasma argon emissions spectrometer which it had been using for over a year for a number of surveys. This regional laboratory developed and maintained both the quality assurance program and the data file for all 21 industries. The samples are collected in plastic containers and originally were preserved with nitric acid before shipment. However, U S . Department of Transportation ( D O T ) regulations prohibit shipping nitric acid by air in any concentration so this practice has been discontinued. Now these samples
are shipped unpreserved, acidified upon receipt at the laboratory, and are held for one week prior to analysis. Total Cyanides and Phenols. Alkaline preservation at a pH of 12 or greater is necessary for the cyanides when the samples are collected. Again, these preservation requirements run afoul of DOT airfreight regulations. Therefore, these samples are now shipped by surface transportation. They must be analyzed within 24 hours of receipt at the laboratory. Analysis of total cyanides is by the standard colorimetric method. After the sample is acidified it is refluxed for several hours and hydrogen cyanide is collected in a n alkaline solution. Absorbance is measured a t 578 nm in the colored solution produced by adding pyridine and barbituric acid. Total phenols, for the purpose of clarity, are those compounds that are measured by the 4-aminoantipyridine method. Water samples for total phenols are collected in glass bottles, acidified to
Volume 13, Number 4 , April 1979
421
TABLE 4
Tentative monitoring phase methodsa Grwp numbef
Prlme
hlwtty
Concentration
contract-w
p+htant*
method8
R8cIhatlon methods
1
Southwest Research Institute (SWRI)
6 phthalate esters
Extract with CH2CIp
Florisil or alumina
2
Monsanto
7 haloethers
Florisil
3
Hydro-
Extract with CHpCiz - . -- - - Extract with CHpClp
- 9 chlorinated hydrocarbons
-. _._I science
3 nitro-
Banelle
4
___
6
7
~
SWRl
5
I
benzenes and Isophorone ___ 3 nitrosamines
_ _-
Carborundum
TCDD
Battelle
2 benzidines and diphenylhydrazine
_ "
8
___^.
10
11
12
Hydroscience
11 phenols
Florlsil
Fiorisii
Wash with acid and base: carbon andl silica -__ -__ -_ ._- or -._ - - .column Extract with wash extract ;;;it; ethyl acetate acid. at pH 8-9 Make acid wash alkaline & extract with ethyl acetate Extract with 1. Nonefor2 CH2Clzat nitrophenols PH 2
Detectors
cohmlu
Isothermal Gc at two different temperatures Temperature program medGC Isothermal Gc at two different temperatures Isothermal
Gc
Extract with CH2Cl2
_"
Battelle
16 polynuclear aromatics
Extract with CH2CIz; exchange with cyclohexane
SWRI
25 pesticides
Extract with CH2C12
26 purgeabies
1. Purge and
Carborwldum
carborundum *
e
Extract with CH2C12; exchange with -_- _toluene . Extract with CHzC12; exchange with hexane
Ana1yIk.l
Isothermal Gc at two different temperatures Isothermal
1.5% SP225011.95% SP-240 1
ECD
3% SP1000
Electrolytic conductivity
1.59/0 ov111.5% OV-225
ECD
1.5% OV1711.95% Qf- 1
ECD and FID
carbowax 20M
Alkali FID
MS
Gc
_ I
I -
9
-- FtGisil
Analytlcsl method8
Acrolein, a w b nitrile and CFeCIp
2. Silica gel of pentafluorobenzyl derivatives -of_ 9 phenols Silica gei acetonttrlle solvent exchange
Florisil; Collect 3 fractions; Hexane solvent exchange None
trap using lenaxlsilica gel trap or
2. Extract with pentane Direct aqueous injection
Lichrosorb RP-2 reverse
HPLC, lsocratic elution
Phase
1. Temperature program-
1. SP-1240DA
1. FID
2. 5% OV- 17
2. ECD
PerkikElmer-HCODS reverse phase
Fluorescence at two different excitation & emission wavelengths ECD
medm
for 2 nitrophenols 2. Isothermal GCfor9 other phenols _.
~
HPiC, Gradient elution
_-
Isothermal
Gc
__ - - __
"
1. Temper-
ature programmed=
1.5 % SP225011.95% SP-240 1
1YO SP1000
2. Isothermal
Gc None
Electrochemical
Temperature prograrnmed Qc
0.27 % Carbowax 1500
1. FID for nonhalogenated compounds. Electrolytic conductivity for halogenated compounds 2. ECDwithextracts FID
The 1 14 organic priority pollutants are divided into 12 groups;20 labs will verify the methods before the end of this year.
* Diphenylhydrazineis so unstable fhet methoddevelopment work has ceased with it.
EPA recommends that chroroethyl vinyl ether (from Croup 2),the three dichlorobenzenes (from Wwp 3) and dichlorodifluoromethane(from Group 12) be mved to this group. This would raise the number of purgeable Priority Pollutants to 31.
pH 4 with phosphoric acid and chilled. These samples can be shipped by air and they must be distilled within 24 hours after receipt at the laboratory. 4-Aminoantipyridine is added to the distillate and the resulting dye is extracted into chloroform and its absorbance is measured a t 460 nm. Asbestos. Since there are many types of asbestos the first problem was how to define it. Asbestos was defined finally as “fibrous asbestos” and consists of chrysotile. To isolate the fibers, water is filtered through a Nuclepore filter and the retained particulates are carbon coated under vacuum. The organic filter is dissolved with chloroform, leaving the fibers embedded in a carbon film. A portion of the film is magnified 20 000 times with a transmission electron microscope, and the asbestos fibers are identified by selected area electron diffraction. A representative area of the electron microscope grid is counted, and the concentration of asbestos in millions of fibers per liter can be calculated from the size of the water sample. Protocol Reviews. Periodically representatives from EPA, industry and the contract laboratories meet to review common problems, new analytical techniques and the status of all programs. These meetings have provided an excellent forum for the shared experience of the chemists involved in these analyses. I n many, if not most cases, split samples are provided to the industries involved so comparisons of the data and the methodology can be made. T o date no fewer than nine industrial work groups have made important contributions to the ever continuing review and refinement of the analytical protocol. The Verification Phase is designed to provide a basis for developing new source performance standards, pretreatment standards and BAT regulations. Plants within an industrial category are chosen to encompass various treatment technologies and wide geographic areas. In general, only Priority Pollutants identified during the Screening Phase are reanalyzed in their respective industrial categories in this phase. Conventional pollution parameters (for example, BOD, T O C , and pH) a r e also measured along with the Priority Pollutants. The sampling and analytical methods are varied and depend on the chemical process treatment technology being evaluated and the parameters selected for verification. Analytical methods may include those in the Screening Phase protocol, only G C using packed or capillary columns and specific detectors, high
pressure liquid chromatography (HPLC), or any combination of the above. The Monitoring Phase will use less expensive methods than G C - M S whenever possible. Five contracts, totaling $1.5 million, are aimed a t developing and verifying alternate methods to G C - M S for analyzing the organic Priority Pollutants. These methods concentrate on sample cleanup and fractionation prior to analysis. Final identification/quantification will be done using G C and H P L C with specific detectors. The 114 organic Priority Pollutants are divided into 12 groups (Table 4), and methods are trying to be developed that will specifically identify and quantify each of the Priority Pollutants in that group in the presence of interfering organic compounds. T o verify the methods, wastewaters spiked with solutions of each of the groups will be analyzed. Youden pairs of concentrates (two solutions with close but different concentrations) will be used for spiking. Twenty EPA and private laboratories will verify the majority of the methods for all 12 groups before the end of 1979. The EPA will not necessarily be bound by the methods developed for these 12 groups. Hopefully some unification will be achieved by taking the best features of methods developed under these contracts and also under some EPA drinking water analyses contracts. Obviously methods developed for drinking water analyses cannot be used for industrial wastewater analyses without modifications to cleanup procedures. But fewer permutations might be achieved using some of the superior cleanup methods developed under Monitoring Phase contracts and some of the superior chromatographic conditions developed for analyzing drinking water samples for these same compounds. A first draft of the methods for the monitoring phase will b e promulgated this month The first draft of each method was due in December 1978. Starting about that time will be a series of interlaboratory studies to verify accuracy and precision of each method. I f a wastewater contains Priority Pollutants in more than 3 or 4 of the 12 groups, it may be more cost effective for a discharger to self-monitor for them using GC-MS. Ultimately, there will probably be some industrial categories that are served best by CC-MS analyses for self-monitoring, especially in view of
the potential new software programs that automatically perform the identifications and quantifications. With the undertaking of the Priority Pollutant program, the EPA has taken its first step on the long road of using organic analyses for monitoring toxic chemicals in industrial discharges. The Priority Pollutant program is, for the first time, establishing a baseline of information with regard to chemical discharges from industrial point sources. Together with the expanded program covering some 40 publicly owned treatment works (POTWs), an overall picture of the nation’s ambient and source discharges is being provided. The 129 Priority Pollutants are only the beginning of a better way to monitor industrial wastewater discharges. T h e mass spectral data tapes and the stored extracts have yet to be examined. Programs to work with this data will be initiated before this year is out. Through these efforts a further list of compounds may be developed which are of concern to industry, the EPA, and encironmentalists. Perhaps the compounds that are infrequently found can be removed from the toxic pollutant list and others more deserving be added. The methods, of course, will continue to improve as technology advances. A larger and more valid data base will be accumulated. In the end we should have reasonable cost-effective methods for reducing industrial pollution and monitoring for it. And, after all, that is what we started out to do-nobody thought i t would be easy.
Dr. Larry H. Keith ( I ) is manager o f t h e Ana!,,tiral Chemical Dirision at Radian C’orporcition in Austin, T e - ~ a sHe . is also
Choirtitun o j the AC‘S Dirision of Etirirontiietitul Cheniistrj. mid. prior t o joining Kartiun, w r l i e d f o r E P A at the Athens, Grorgia Etii.ironmental Research Lahortrtor),. William A. Telliard ( r ) is chiejof the Energ?’ and Mining Branch, Effluent Giridelinrs Dirision, Enrironniental Protection Agrnc),. Prior to his present position. he w r k e d in the Office of Water Enjorrenient, both in the Pert7iit.s Dirision atid the Etforcenient Dicision. He joined the agetic?. in 1972. Volume 13, Number 4 , April 1979
423
