Land use of wastewater and sludge Here is a review of current technologies, treatment performance, and research needs for these municipal wastes . _ ... -
Ronald W. Crites Grorpe " S . tiolte ond Associolrs 1700 L Sweet
Sacramento, Cal$ 95814 Serious research concerning the use of municipal wastewater and sludge on land started in the late 1960s. In July 1973, a workshop was heldat theuniversityof lllinois(1) to define the existing state of knowledge and determine research needs for land treatment of municipal waste. I n the ensuing IO years, much information on the technology has been developed, and many questions posed have been answered. Nevertheless, not only do some of the research needs remain unfulfilled, but several new issues have been raised. During the 196Os, the technology of land treatment was viewed mainly as a disposal technology with all necessary treatment carried out before land disposal. Similarly, land application of sludge was seen as a disposal approach only; little thought was given to the beneficial uses of sludge on land.Currently, there isa much wider understanding of the ability of soil systems to treat wastewater and acceptance of the view that sludge can be safely and beneficially applied to cropland, forest land, and disturbed lands.
Land treatment of wastewater The three land treatment processes for wastewater are slow rate, rapid infiltration, and overland flow. During the early 1970s. only slow rate (irrigation) and rapid infiltration were in use for municipal wastewater. i Over the next 10 years, overland flow ! land treatment emerged as an effec140A
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tive treatment process for screened raw wastewater as well as primary and secondary effluent. A comparison of the number of municipal land treatment systems existing in 1972 with those in 1981 is presented in Table l . Slow rate. Slow rate land treatment is the controlled application of wastewater by sprinkler or surface means to a vegetated land surface. Systems are designed to avoid offsite runoff of the wastewater. A portion of the applied wastewater percolates to the subsurface, and the remainder is used by the vegetation. The largest slow rate system, the Metro system in Muskegon County, Mich., went into operation in 1974 to treat 1.2 m3/s [27.5 million gallons per day (mgd)] of domestic and industrial wastewater ( 4 ) . Center pivot sprinklers apply aerated lagoon effluent onto 2240 ha (5540 acres) of land on which field corn is planted annually. The underdrain system (which is generally unique to slow rate systems), consisting of corrugated polyethylene tubing with nylon sock-type filter sheaths, was installed at a 150m (500-ft) spacing and at depths of 1.5-3.7 m (5-12 ft). Problems with drainage have limited the hydraulic capacity of the site ( 4 ) . The system is to be expanded to a 2.1-m3/s (49mgd) capacity by the addition of a rapid infiltration system in the welldrained north area. Another development in the 1970s and early 1980s was the full-scale use of forested land for slow rate land treatment. This grew out of research carried out during the 1960s and 1970s at the Pennsylvania State University ( 5 ) and similar research undertaken in 1973 in Georgia (6). On the basis of this research, a full-scale 0.86-m3/s (19.6-mgd) forested slow rate system was designed for Clayton County, Ga. The subsurface flow from this system, placed into operation in 1981, augments stream flow, which is used for water supply for the community ( 7 ) . Slow rate land treatment normally requires 2.6-3.5 ha/m% (150-200 acres/mgd). To minimize the capital costsof new slow rate systems, several have been developed to irrigate private land. The cost of purchasing the land is thereby avoided. In 1979, a 525-ha (1300-acre) system was developed a t Mitchell, S.D., where the farmers own the land and operate and maintain the center pivot machines. Other systems using private land include El Reno, Okla., Vandalia, Ma., Lubbock, Tex., and Petaluma, Calif.
(8).The city of Petaluma saved more than $1 million on the capital costs of installingaslowratesystemon222 ha (550 acres) by not purchasing the land. Rapid infiltration. Rapid infiltration is the application of wastewater to permeable soils, such as sands or sandy loams, for treatment in shallow spreading basins. Wastewater undergoes treatment by chemical, physical, and biological processes as it travels through the soil. Vegetation is not normally a part of rapid infiltration, because loading rates are too high for nutrient uptake by plants to be effective. There are, however, instances in which vegetation plays an integral role in stabilizing surface soils and maintaining high infiltration rates. The treated water generally flows through the subsurface until it joins a surface stream. The quality of this water is typically very good and generally comparable to tertiary effluent (9). A major advance in the use of rapid infiltration in the 1970s arose from the realization that with application of primary effluent, the quality of the percolate was usually comparable with, and often better than percolate from systems using secondary effluent. Formanyyears, theuseofprimary effluent at Ft. Devens, Mass. (10), and Hollister, Calif. ( / I ) , and untreated wastewater a t Calumet, Mich. ( / 2 ) ,has resulted in high-quality percolates. Primary effluent enhances the denitrification reaction in the soil and allows greater nitrogen removal (3). Another development was the use of underground aquifers for wastewater storage, followed by recovery and reuse of the water. Research at Phoenix, Ariz., has shown that intermittent infiltration, followed by recovery with wells, can produce highquality water suitable for unrestricted irrigation (13). A similar system employing ponds, rapid infiltration, and recovery wells is in use in the Dan region of Israel ( 1 4 ) . This underground storage can allow cost-effective reuse of the treated water for crop irrigation. Overland flow. Overland flow is a fixed-film biological treatment process by which wastewater is applied at the upper portions of grass-covered slopes and allowed to flow down the slope to runoff collection ditches. The wastewater is treated by physical, chemical, and biological means as it flows in a thin sheet down the slope, which is between 30 and 45 m (100I50 ft) long. Slowly permeable soils
are used, and slopes have a grade of 28%. As indicated in Table 1, no municipal overland flow system was in use in the U S . in 1972. EPA conducted the first research on overland flow treatment of municipal wastewater a t Ada, Okla. This stimulated research and pilot projects at several other locations during the mid-1970s (15). A list of research and demonstration systems is presented in Table 2. Most of the research at these facilities has been completed. With this field research plus laboratory-scale research and development concerning overland flow for treatment of certain industrial wastes, there was a substantial evolution of the technology. By the late 1970s, research at Hanover, N.H., and Davis, Calif., led to rational design equations based on slope length and application rate (16, 17). These equations, based upon fixed-film biological kinetics, predicted removal of irganic matter over shorter distances,
Environ. Sci. Technol.. VoI. 18. No. 5 , 1984
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at higher application rates than are normally thought possible, and indicated the degree of conservatism in the current empirical design approach. The largest overland flow system treating municipal wastewater is the one at Davis, Calif., designed for 20 000 m3/d ( 5 mgd) (18). Oxidation pond effluent is applied at the top of the slope through gated aluminum pipe. The gated pipe allows surface distribution, which saves energy compared with over sprinkler application. Problems related to the physical design of the Davis system have been detailed recently. Land treatment performance In the early 1970s, very little was known about the removal of wastewater constituents by land treatment. As a result of research, pilot systems, and investigations into the performance of long-term operations, there
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is now a better understanding of the functioning of land treatment processes. BOD and suspended solids. Land treatment processes are very efficient in removing biodegradable organics and suspended solids. Typical removals and concentrations at selected sites are presented in Table 3. Removal mechanisms include filtration, adsorption, and biological oxidation. The removals termed “typical” in Table 3 for slow rate and rapid infiltration are based on applying primary effluent. Existing systems at Dickinson, N.D., Muskegon, Mich., Lake George,N.Y., andPhoenix,Ariz.,use secondary effluent. At Hanover, N.H., the slow rate systems have received primary effluent and have achieved results comparable to systems in which secondary effluent has been applied. For overland flow, screened raw wastewater is typically applied (see Table 3).
Nitrogen. Both ammonia and total nitrogen removal occur in all land treatment processes. In slow rate, the principal mechanism is uptake by crops; denitrification is generally of secondary importance. In rapid infiltration and overland flow, denitrification is the principal nitrogen removal mechanism. Removals of ammonia and total nitrogen are presented in Table 3. At Hanover, N.H., the slow rate test cell was loaded with primary effluent on a year-round basis (20). Higher nitrogen removal could be expected for systems that store wastewater during the nongrowing season. Nitrogen removals for the four rapid infiltration systems illustrate the range typically found with existing systems. The removals where primary effluent is applied (Ft. Devens, Mass., and Hollister, Calif.) are higher than the 50% normally expected. At Hollister, the 93% total nitrogen removal is attributable, in part, to the avail-
ability of BOD (220 mg/L in the applied primary effluent) to drive the denitrification reaction. Overland flow is also efficient for nitrogen removal; 80% is a typical removal. At the research sites listed in Table 3, screened raw wastewater was applied at Ada, Okla., and at Easley, S.C., on a year-round basis. At Hanover, N.H., primary effluent was applied from May through October. Wintertime applications were tried; however, the removal efficiencies decreased to about 30% for total nitrogen and 37% for ammonia. Phosphorus. Both the slow rate and the rapid infiltration processes remove phosphorus from applied wastewater very efficiently. The mechanisms for removal are adsorption and chemical precipitation. Overland flow, as shown in Table 3, is less efficient for phosphorus removal because of the limited contact between the wastewater and the adsorption sites within the soil. Removals down to 1-2 mg/L can be obtained by the addition of alum to the applied wastewater to precipitate the phosphorus ( 2 1 , 2 2 ) . Pathogenic organisms. The removal of pathogenic organisms through land treatment, including bacteria and viruses, is accomplished by filtration, adsorption, desiccation, radiation, predation, and exposure to other adverse conditions. Slow rate systems are the most efficient, removing 4-5 logs (104-105) of fecal coliform concentration (3). Rapid infiltration is somewhat less efficient, typically removing 2-3 logs of fecal coliforms. Overland flow removes about 90% of the applied fecal coliforms. Trace organics. The removal of trace organics in land treatment systems is achieved by mechanisms of .adsorption, biodegradation, photodecomposition, and volatilization. On the basis of research done at Hanover, N.H. (20),and at Muskegon County, Mich. (23), it appears that slow rate systems are very efficient in removing trace organics. At Hanover, the test plots were monitored for trace organics in the wastewater, beforeand after spraying, and in the percolate (Table 4). The percolate was essentially free of the organics applied with the wastewater after passage through 1.5 m (5 ft) of soil. In Table 4, the effectiveness of removal by volatilization can be seen by comparing concentrations before and after sprinkling. For rapid infiltration, removals of trace organics are not as well docu-
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mented, except for sampling at Phoenix, A r k , and Ft. Devens, Mass. (24). At Ft. Devens removals averaged 96% for the compounds measured (25).A three-year research program comparing removals of trace organics in rapid infiltration with those applying secondary effluent is under way at Ontario, Calif. (26). Overland flow is also effective for the removal of trace organics. At Hanover, N.H., removals ranged from 94 to 99% for the compounds measured. A model was developed to predict trace organics removal (27). Trace elements. Trace element removal (mostly metals) in the soil involves the mechanisms of adsorption, precipitation, ion exchange, and complexation. Because the adsorption of trace elements occurs on the surface of clay minerals, metal oxides, and organic matter, fine-textured soils have greater removal capacities for trace elements than sandy soils have. Slow rate systems, which more often involve finer-textured soils than do rapid infiltration systems, show higher removals (80-95%) as a result of lower loading rates and more adsorption sites. For overland flow systems, removals have been shown to range from 60 to 90% depending upon the element and the loading rate (22). Land treatment research needs Research needs for land treatment of municipal wastewater include hydraulic aspects of soil systems and prediction of process performance. Other aspects of land treatment requiring research are preapplication treatment and crop management. Infiltration rates. Both slow rate and rapid systems rely on wastewater infiltration rates thatcan be predicted and maintained. Overland flow systems are designed for minimal infiltration of wastewater.
Current design practice for slow rate and rapid infiltration is to measure the saturated infiltration rate in the field using one of a variety of techniques (3). Design values of infiltration and percolation are then estimated from soil properties using a small percentage of the measured rates. This small percentage (2-10% depending on the test) accounts for the needed drying time between applications, the variability of the actual soil permeability within the site, and the potential reduction of infiltration rates with time. More research, similar to that conducted on a slow rate system at Apple Valley, Minn., needs to be conducted on long-term maintenance of infiltration rates (28). That research with corn and grass grown together has shown how soil sealing, and thus reduction of infiltration rates, can be prevented. Field verification of the relationship between predicted and actual long-term infiltration rates for rapid infiltration is needed. Methods of preparing rapid infiltration basins in fill must be developedsothat theinfiltration rateofthe native soil can be retained. Experience has shown that conventional methods of construction with large earth-moving equipment result in compacted soil, which may have an infiltration rate lower than the native soil by an order of magnitude. This is especially critical when the soil contains significant (more than about 10%) amounts of clay. BOD and suspended solids removal. Removals of BOD and suspended solids are well defined for slow rate and rapid infiltration systems. Overland flow has difficulty in consistently removing suspended solids (specifically algal solids) from oxidation pond effluents (29, 30). The free-floating green algae are poorly removed, Environ. Sci. Technol.. Vol. 18, No. 5 . 1984
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whereas filamentous algae tend to be filtered out by the grass or settle out on the overland flow slope. Research is needed on the type of algae, loading rates, potential for pond-primary effluent mixtures, and the effects of seasonal storage on algae removal by overland flow (29). Nitrogen removal. Although intensively studied, management of nitrogen remains a subject replete with many topics needing additional clarification. Denitrification rates, monthly uptake by crops, and nitrate dilution with subsurface flows represent research topics for slow rate land treatment. Prediction of nitrogen removal, interrelationships between loading rates, loading cycles, temperature, carbon to nitrogen ratios, and optimization of nitrification and denitrification are topics for research on rapid infiltration (36). For overland flow there is a need for performance documentation on fullscale systems in various climates. Another research need involves prediction of the needed slope lengths and application rates and cycles for optimum nitrogen removal. Phosphorus removal. Reliable and cost-effective measures to increase phosphorus removal by overland flow are needed. For slow rate systems with phosphorus removal limits, such as Muskegon County, Mich., the question of how long the removal will continue and how removal magnitudes will change with time needs to be answered. For rapid infiltration, the prediction of the renovated water concentration of phosphorus requires more research. Existing models on phosphorus removal require field verification. Pathogenic organisms removal. For slow rate systems the removal of pathogenic organisms in the soil profile is not a design constraint ( 3 ) .Although some concern remains over health effects from aerosols, much positive information on the relative safety of the process has been published (31-33). For example, the previous position that aerosols were related to increased incidence of illness in Israel has been reversed (34).No incidence of disease has been attributed to land treatment in this country (35). Research on virus and bacterial transport in rapid infiltration has shown virus movement under some conditions (32,35).The conditions of movement and survival of pathogens in soil and groundwater at land treatment sites need further study. In addition, risk assessment analyses should be conducted on land application of 144A
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wastewater to various types of rapid infiltration sites. In overland flow there is only 8590% removal of microorganisms applied with the water. The survival of helminths and other pathogens on overland flow slopes has not been studied. Trace organics and elements removal. Trace organics removal in rapid infiltration needs further study because of potential effects on groundwater quality, and some research is under way (26). Removals by slow rate and overland flow systems have been documented, but specific removal mechanisms and removals of other priority pollutants should be studied. Long-term removals and the fate of removed pollutants need further research (36). Removals of most trace elements, especially metals, have been demonstrated in varying degrees for all land treatment processes. A future research area is the long-term fate of pollutants that are retained in the soil after a land treatment site has been closed. Preapplication treatment. Research is needed on low-cost methods of wastewater treatment prior to land application (preapplication treatment). Many low-cost methods, such as aerated lagoons, remove BOD and suspended solids and prepare the wastewater for disinfection. But so far, there are few low-cost methods that will reduce the concentration of nitrogen (especially in high-nitrogen wastewaters) or pathogenic organisms. This is especially true for slow rate systems, because nitrogen loadings are often limiting in the system design. In addition, disinfection or reduction of the concentration of pathogenic organisms is often required for slow rate systems. This need is critical for small-scale systems in which preapplication treatment costs often exceed land treatment costs. Crop management. Many aspects of crop selection and crop tolerance to specific pollutants have been considered over the past 10 years ( 3 ) .More research is needed on the long-term phytotoxicity of elements such as boron, copper, nickel, and zinc in both forest and agricultural slow rate systems. Management of corn-grass intercropping systems to optimize nitrogen removal needs more extensive demonstration. Such intercropping systems have been studied in Michigan and Minnesota (3, 36), but the management techniques need to be refined and tested in other climates. Management of forested slow rate
systems requires much research into areas such as whole-tree harvesting and short-term (less than 10 years) rotation forests. The longevity of a forest ecosystem that treats wastewater is unknown, and the management of the understory (under the trees) vegetative cover may play a very important role in long-term treatment ( 3 ) . Land application of sludge Since 1973, there have been significant developments in the use of municipal sludge on agricultural, forest, drastically disturbed, and dedicated lands. There are, however, a number of issues that remain to be resolved. Agricultural cropland. A great deal of research has been conducted on agronomic aspects of sludge use, including trace element uptake and translocation into the food chain (35). Many of the trace elements are also micronutrients, such as zinc, which improve plant growth and the feed value of the crops. Other metals, such as cadmium and lead, are of concern because of the potential of introducing them into the human food chain (37, 38). Crops vary in their uptake of cadmium. Some varieties exclude more cadmium than others. There are data from which it can be concluded that cadmium uptake can be genetically controlled and that crop varieties can be selected for their low uptake (38). During the past 10 years researchers have discovered two major errors in experimental methods of researching toxic element uptake by plants (39). The first error, called the “salt vs. sludge” error, occurs when soluble heavy metal salts are added to soil. Such salts are nearly always taken up by plants in greater amounts and show more toxicity than when the metal is applied in equal amounts in sludge (40). Sludge supplies organic matter and iron and manganese oxides to increase the sorption of metals, thereby making them less available for plant uptake. Even when added metals are incubated with digested sludge, the plant uptake is greater than when metals are present initially in the sludge (41). The second, “greenhouse vs. field,” error, results in higher contents of metals in crops grown in the greenhouse compared with those in crops grown in the field for the same soil, sludge, and crop (40).This appears to result from confinement of plant roots in the small volume of soil, fertilizer and salt effects, and abnormal water-
ing patterns (40).I n addition to these errors, soils, sludges, and crops interact differently when high metal sludgesare used from the way they do when low metal sludgesareused ( 4 0 ) . In light of these errors and the fact that trace metal loadings have been a major limiting criterion for design of land application systems, there remains the issue of what appropriate levels of trace metals in sludges and soils are. Ultimate site capacities are also influenced by cumulative metal loadings, and acceptable long-term loading rate criteria need to be reassessed: The EPA sludge process design manual ( 4 2 )establishesa design basis for nitrogen applications to cropland. Thisinvolvesthe typeofsludgeand its nitrogen content, and a determination of the the first-year availability of nitrogen. The resulting nitrogen availability is matched against the crop needs for nitrogen. This design manual is the culmination of several technology transfer publications including t h e 1978 “Sludge Treatment and Disposal” document ( 4 3 ) . The 1978 document included current guidance on sludge properties, planning and site selection, and application methods ( 3 6 ) . Forest land. Relatively little work has been done on land application of sludge in forests. Research in Michigan ( 4 4 ) and Washington (45) has made a good start, but much work remains to be accomplished. Wooded areas are traditionally not fertilized: thus, nitrogen cycling with sludge additions needs to be studied. Also, forests are out of the food chain for humans, so higher cadmium loadings may be possible ascompared with agricultural soils. Drastically disturbed land. Surface-mined and other disturbed land can be revegetated with the aid of municipal sludge. Unlike agricultural or forested sites, the drastically disturbed site must usually be regraded for a one-time sludge application. With this application, the objective is to create a large pool of nutrients to supply the vegetation for more than one year so that additional sludge is not needed. As a result, it is important that the sludge release its organic nitrogen slowly in order not to create a nitrate problem in the percolate from the site. Ideal sludges are composted or anaerobically digested sludges that tend to be relatively low in total nitrogen. In Maryland, for example, with municipal sludge compost, plants were grown on an acid strip mine in
!
Cornpasling: Piihlic healrh remains n sludge use issue
sufficient quantity to qualify it as being revegetated (80% ground cover and 10% legumes after two years) ( 4 6 ) . A Fulton County. Ill., site for land application of sludge had been strip-mined before the Metropolitan Sanitary District of Greater Chicago purchased the 2898 ha (7 I56 acres) in 1970. Extensive research on the microbiological aspects of applying anaerobically digested sludge to the land was conducted at this site ( 4 7 ) . Dedicated land application. Sludge application rates at dedicated sites are significantly higher than for agricultural or forested sites. The limiting factors are usually the water content ofthesludgeand theabilityofthesoil to accept the organic loading without odor production. The objective is to provide minimal pretreatment of the sludge and apply it at the maximum rate consistent with organic decomposition. A facility at Sacramento, Calif., is a case in point ( 4 2 ) . Sludge use issues Sludge use issues continue to center on the public health concerns over cadmium, lead, toxic organics, and pathogens. Other issues include design criteria for forest applications, nitrogen cycling in forests. application rates and plant selection for drastically disturbed lands, and reassessment of the phytotoxicity standards for metals. Cadmium has dominated the regulatory and research field since the mid- 1970s. Reassessment of the models and regulatory findings is recommended on the basis of current data (36-38, 40. 4 / ) . Specifically, the use of low-cadmium sludges appears to contradict many of the assumptions on uptake and accumulation that were made during the development of the regulations. Uptake of lead by plants is not a problem unless lead levels are very high (40). The health concern over lead is from surface accumulation and direct ingestion. This concern can
be avoided by injection of the sludge into the root zone. Toxic organics in sludge such as polychlorinated biphenyls (PCBs) can bea problem ( 3 6 , 4 2 ) .Research is under way at Muskegon County on the fate of such toxic substances in land-applied sludge. The feeding of site-grown crops toanimals isunlikely to pose a health problem, but grazing animals could accumulate significant levels of toxic organics if the sludge is surface-applied (48). Pathogens and their survival in sludge-soil mixtures continue to be major research topic. Regulations on sludge stabilization and restrictions on its use for food chain crops have been promulgated by EPA ( 4 9 ) . Design criteria for forest application. Application rates to agricultural land are limited either by nitrogen or cadmium loadings. For forests, application rates have not been developed sufficiently to determine what the limiting loading will be. Nitrogen cycling-including plant uptake, soil storage, and denitrification-has not been established. Loadings of trace elements such as boron may be limiting to some tree species (36). Phytotoxicity standards for metals. The phytotoxicity standards in design manual ( 4 2 ) need reassessment in light of current information. Research is needed to define the appropriate values for design. Current standards are very conservative, and higher concentrations will probably be found to be acceptable (40). Designing with confidence Substantial progress has been made in the understanding of land treatment performance capabilities in the past IO years, particularly for overland flow treatment of municipal wastewater. Land treatment processes can be designed to be efficient, cost-effective alternatives for nutrient removal. Individually or in combination, they can remove nitrogen, BOD, SS, phosphorus, trace metals, and Environ. Sci. Technol.. VoI. 18. NO. 5. 1984
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trace organics. Although additional information i s s t i l l needed on specific issues, the technology i s well enough developed to allow systems to be designed with confidence.
Acknowledgment Before publication, thisarticle was read and commented on for suitability as a n ES&T feature b y F r a n k H u m e n i k of N o r t h Carolina State University. Raleigh, N.C. 27650, a n d R a y m o n d C. L o e h r o f C o r n e l l University, Ithaca, N.Y. 14853.
References (I)“Proceedings of the Joint Confercnce on Recycling Municipal Sludges and Effluents on Land”: EPAIUSDAlNational Association of State Universitics and Land-Grant Colleges: Champaign, 111.. July 9-13. 1973. (2) Pound, C.E.: Crites. R.W. “Wastewater Treatment and Reuse by Land Application,” RSK ERL. EPA-660/2-73-006b; U.S. EPA: Ada, Okla., Aug. 19 3 (3) “Process Design Manual for Land Treat. ment of Municipal Wastcwater.” EPA625/1-81-013: U.S. EPA: Washington. D.C.. ,~~~ Oct. 1981 (4) Demirjian. Y.A.: Kendrick, D.R.; Westman. T.R. In “Proceedings of the American Society of Agricultural Engineers Summer MeetinR”: American Societv of Aericultural Engineers: Orlando. Fla.. J h e 21-24. 1981. (5) Kardos. L.T. e t al. “Renovauon of Sccondary Effluent for Reuse as a Wate;Rc. source.” EPA-660/2-74-016; US. EPA: Washington. D.C., Fcb. 1974. (6) Nutter. W.L. et al. In “Proceedings of the International Symposium on Land Treatment of Wastewater:’ Val. I: US. Arm” Corps of Engineers: ‘Hanover; N.H. Aug. 20-25.1978. (7) Crites, R.W.“Slow Rate LandTreatment: A Recycle Technology”; U.S. EPA: Washington, D.C.. 1981. (8) Crites, R.W. “Innovative and Alternative Treatment at Petaluma. California”: presented at the Hawaii Water Pollution Control Association Annual Confcrence. Honolulu, Hawaii, Jan. 28. 1981 (Y),Crites. R.W; Meyer. E.L.“Rapid Infiltration Land Treatment: A Recycle Teehnology”; U.S. EPA, in press. ( I O ) Salterwhite. M.B.; Condikc. B.J.: Stewart. C.L. “Treatment of Primary Sewage Effluent by Rapid Infiltration”: U.S. Army Corps of Engineers. Cold Regions Research and Engineering Laboratory: Hanover, N.H.. Dcc. 1976. (11) Olson.J.V.;Critcs.R.W.;Levine.P.E.J. Enciron. Eng. Diu. Am. Soc. Citi. Eng. 1980. 106(5),885-99. (12) Baillod. C.R. et al. In “Land as a Waste Management Alternativc”: Ann Arbor Science: Ann Arbor. Mich.. 1977. (13) Bouwer. H. et al. J. Wafer Pollur. ( b n fro1 Fed. 1980.52(10). 2457-70. (14) Idelovitch. E. 1n“Proceedingrofthc National Canfcrence on Environmental Engineering”: American Society of Civil Engineers: Atlanta.Ga..July8-10. 1981. (15) Thomas. R.E.. Jackson. K.: Penrad. L. “Feasibility of Overland Flow for Treatment of Raw Domestic Wastewatcr,” EPA66012-74-087; EPA: Ada. Okla.. July 1974. (16) Martel. C.J. et al. “Development of a Rational Design Procedure for Overland Flow Systems.’’ CRREL Report 82-2: US. Army Corps of Enginecrs: Hanover, N.H.. Feb. 1982. (17) Smith, R.C. In “Proceedings o f t h c Na~
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tional Seminar on Overland Flaw Tcchnology for Municipal Wastewater”: Dallas. Tcx..Sept. 16-18. 1980. (18) Smith. R.G.: Schroeder. E.D. J . Warer Pollar. Control Fed.. 1983,55(3). 255-60. (19) Leach. L.E.: Enfield.C.G.; Har1in.C.C. Jr., “Summary of Long-Term Rapid Infiltration System Studies.“ EPA-600/2-80165: U.S. EPA: Ada. Okla.. July 1980. (20) Jenkins. T.F.. Palazzo. A.J. “Wastewater Treatment by a Prototype Slow Rate Land Treatment System.”CRREL Report 81-14: US. Army Corps of Enginccrs: Hanaver. N.H..Aug. 1981. (21) Thomas, R.E.; Bledsoe. B.: Jackson. K. “Overland Flow Treatmcnt of Raw Wastewa!cr with Enhanced Phosphorus Removal. EPA-600/2-76-131; U.S. EPA: June 1976. (22) Peters, R.E.: Lee. C.R.: Bates, D.J. “Field Investigations of Overland Flow Treatment of Municipal Lagoon Effluent.” Tech. Rep. EL-81-9 US. Army Engineer Waterways Experimcnt Station: Vicksburg, Miss..Sept. 19x1. (23) “Preliminary Survey of Toxic Pollutants at the Muskegon Wastewater Management System”: Robert S. Kerr Enviranmcntal Research Laboratory. US. EPA: Ada. Okla., 1977. (24) Bouwer. E.J.: McCarty. P.L.: Bauwuer. H. Presented a t the Water Pollution Control Confcrcnce. Detroit, Mich. Oct. 4-9, 1981. (25) Tomson. M.B. et al. Presented a t the 3rd World Congresson Water Resources, Mexico City. 1980. (26) Crites, R.W. In “Artificial Recharge of >, T., Ed.: Ann Arbor , Mass.. in
ment”: American Socicty of Civil Engineers: Orlando. Fla.. July 20-23. 1982. (28) Marten. C.C. et al. Agronomy J. 1981, 1 ,797-97 ,7 _ ___
(29) Smith, R.G.; Schroeder. E.D. “DemonstrationoftheOverland Flow Process forthe Treatment of Municipal Wastewater-Phase II Ficld Studics”: California Statc Water Resources Control Board: Sacramcnto, Calif., 1982. ( 3 0 ) Witherow. J.L.: Bledsoe. B.E. J. Wafer Pollur. ConrrolFed. 1983,55(10). 1256-62. (31) Crites.R.W.;Uiga,A.“AnApproachfor Comparing Health Risks of Wastcwater Treatment Alternatives-A Limited Comparison of Health Risks Between Slow Rate Land Treatment and Activated Sludge Treatment and Discharge.” EPA-430/9-79009: MCD-41; U.S. EPA: Washington, nc -. -. , i o,.m,. (32) Kowal. N.E. “Health Effccts of Land Treatment: Microbiological.” EPA-6001 I81.1155. NTIS NO.p ~ s m 3 9 4 9U.S. ; EPA: Cincinnati. Ohia. July 1981 ( 3 3 ) Reed, S.C. I n “Technology Transfer Seminars. Land Treatment of Municipal Wastcwater Effluents”: US. EPA and US. Army Corps of Engineers: Cincinnati, Ohio. June 1979. (34) Fnttal. B. et al. In”ProceedingrofWa1er Reurc Symposium II: A W W A Rcsearch Foundation”; Denvcr. Calo.. August 198 I:
ings 01 the Third Annual Madison Confercnce of Applied Research and Practice on Municipal & Industrial Waste“; University of Wisconsin: Madison. Wis., Sept. 10-1.2. 1980. (38) “EffectsofSewageSludgeon the Cadmium and Zinc Content o f Craps,” EPA60018-81-003; Council for Aericultural Science and Technology. U.S- EPA: WashD Feh 19x1 inelan. D ~ C . ~ ~ ~ , ~ (39) “Application of Sewage Sludge to Cropland: Appraisal of Potential Hazards ofthe Heavy Metals to Plants and Animals.” Re. port No. 64: Council far Agricultural Scienceand Technology, Iowa State University: Ames. Iowa. No”. I S . 1976. (40)Logan, T.J.: Chancy, R. In “Workshop On Utilization of Municipal Wastcwater and Sludge on L a n d : Denver, Cola.; U.S. EPA: Washinetan. D.C... in DICES. (41) Bloomfieid. C.; McCrath. S.P. Environ. Pollur. Bull. 1982.3, 193-98. (42) “Process Design Manual on Utilization of Municipal Sewagc Sludge on Land.” EPA-625/1-83-016; U S . EPA: Cincinnati. Ohio, Oct. 1983. (43) “Principles and Design Criteria for Sewage Sludge Application on Land.” EPA62514-78-012 I n Sludge Trear. Disporol, ~~~
~~~
1 . . .9. ,7- I~7. inr,
(44) Uric, D.H. In “Utilization of Mu’nicipal Sewage Efflucnt and Sludge on Forest and Disturbed L a n d . Sooner. W.E.. and Kerr. S.N., Eds.; The Penn&nta State Univer: sily Prcss: University Park, Pa.. 1979: pp. 717.
University Press: University Park. Pa., 1979: pp. 35-45. (46) Cricbel,G.E. etal. In “Utilization of Municipal Sewage Effluent and Sludge an Forest and Disturbed Land”: Soppcr. W.E.. and Kerr. S.N.. Eds.; Thc Pcnnsylvania State University Press: University Park, Pa., 1979. pp. 293-306. (47) Peterson. J.R.; Pietr, R.I.: Luc-Hing, C. In “Utilization of Municipal Sewagc Effluent and Sludge on Forest and Dirturbcd L a n d , Sopper. W.E.. and Kerr. S.N.. Eds.: The Pennsylvania State University Press: University Park. Pa.. 1979; pp. 359-68. (48) Kowal, N.E. I n “Workshop on Utilizatianof Municipal Wastcwaterand Sludgeon L a n d ; Denver. Cola.; U.S. EPA. in press. (49) U S Environmental Protcction Agency. 40 CFR Part 257: Fed. Regisr. 1979, 44 (Sept. 3).
.
Vol.. 3. pp. 2200-15.
(35) Gerba, C.P.: Coyal. S.M. I n “Artificial Recharge of Groundwater”: Asano. T.. Ed.: Ann Arbor ScienceIButtcrworths: Woburn. Mars.. in press. (36) Pound.C.E.:Criffes, D.A.:Critcs. R.W. I n “Workshop on Utilization of Municipal Wastewater and Sludge on Land”: Denver, Cola.; U.S. EPA, in press. (37) Crites. R.W.: Alpert. M.E. In “Pracecd-
Ronald W. (rifc.s w w i n y l his M S and Engineerr D q y w in uwimnmenial engineeringfrom Srunford L‘niwrsiry. H e has wrirren numerous reporrs on land applicarion. and was rhe senior aurhor of fhe E P A Process Design Manual on Land Trearmenr of Municipal Wasrewarer. Crires is currenrly engineering manager for George S. Nolfe and Associares. consulring engineem in Sacramenro, Calif. Envimn. Sci. Technol.. VoI. 18. NO. 5. 1984
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