ECHNOLOGY The Bridge Between Research and Use W. U.S. ENVIRONMENTAL PROTECTION AGENCY OCTOBER 1, 1374 NEW SLUDGE TREATMENT AND DISPOSAL DESIGN MANUAL TO BE FEATURED AT WPCF CONFERENCE The EPA Technology Transfer Program will once again participate in the annual conference of the Water Pollution Control Federation being held this year in Denver, Colorado, in October. The new Technology Transfer Process Design Manual for Sludge Treatment and Disposal will be introduced and distributed at the Denver meeting. There will be no change for this new "blue book." The new sludge manual will be comprehensive in scope and include such topics as physical and chemical properties, thickening, stabilization, conditioning, dewatering, reduction, final disposal processes, and case studies. New chemical sludges and oxygen sludges will be covered in addition to the various types of equipment required to perform the basic processes. All new processes and equipment will be included as well as cost data and all applicable data and information from the EPA research and demonstration program. Host region for this years conference will be EPA's Region VIII. John A. Green, the Regional Administrator, will be on hand at the opening of the conference, which annually attracts thousands of the nations top pollution experts. On October 3,1971, John A. Green was appointed as the first Regional Administrator of the Environmental Protection Agency, Rocky Mountain- Prairie Region, by EPA National Administrator, William D. Ruckelshaus. As Regional Administrator, Green is the highest level federal official concerned with protecting the environment in the states of Colorado, Utah, Montana, Wyoming, North Dakota, and South Dakota. He is responsible not only for the agency's leadership in environmental management, but, also, for planning and integrating important strategies and priorities in the six-state region. Green directs the development and administration of a coherent, unified approach to the interrelated problems of air and water pollution, pesticides, radiation, solid waste and noise. Immediately prior to being appointed Regional Administrator, Green served as senior staff advisor John Green, EPA, Region VIII, Administrator. to the EPA Assistant Administrator for Categorical Programs in Washington, D.C. Green was responsible for guiding the program's control of a wide variety of environmental contaminants, including pesticides, radiation, and solid waste. Green has also served as Director of Management, Federal Water Quality Administration in Arlington, Virginia. As Director, Green supervised special studies aimed at improving the efficiency and effectiveness of the nation's "Clean Water" program as well as overseeing the development of a long-range strategy for the attainment, nationally, of the Federal Water Quality Standards. ------- Choosing the Optimum Friancia! Strategy VvY- SULFIDE CONTROL MANUAL AVAILABLE The Technology Transfer Process Design Manual for Sulfide Control in Sanitary Sewerage Systems, prepared by Pomeroy, Johnston, and Bailey of Pasadena, California, is currently being distributed. This Manual includes information for all feasible alternative designs that can be used to control sulfides and minimize their effects in both new and existing sewerage systems. Specific topics covered include: Characteristics and Properties of Hydrogen Sulfide; Occurrence and Effects of Sulfide in Sewers; Investigation in Existing Systems; and Design of Sewer Systems to Prevent Sulfide Problems. Case histories, examples, and cost estimates are presented to substantiate the "how-to" approach of this manual. individuals interested in obtaining, at no charge, a copy of the Sulfide Control Manual should fill out the appropriate form in the back of this publication and forward it to Technology Transfer, U.S. Environ- mental Protection Agency, Washington, D.C. 20460. INDUSTRIAL SEMINAR PUBLICATIONS ON UPGRADING MEAT PACKING TO REDUCE POLLUTION NOW AVAILABLE A three part publication covering In-Process Modification and Pretreatment, Waste Treatment, and Choosing the Optimum Financial Strategy is now available. These publications follow others developed from the seminar program where technical sessions were given covering the above topics. Previous publications were on Reducing Pollution in the Metal Finishing Industry and the Poultry Industry. The publications are particularly oriented toward owners, managers, superintendents, and engineer- ing and operating staffs of meat packing facilities. The seminars and the publications are intended to inform the small industry of the varied in-plant process modifications and control alternatives available to meet environmental standards. Add-essing these topics should help the facility formulate their control alternatives prior to detailed design considerations. To order these publications, use the order form at the rear of this publication. TECHNICAL CAPSULE REPORT ON POLLUTION ABATEMENT IN A BREWING FACILITY NOW AVAILABLE A technical capsule report on the pollution abatement program progress Adolph Coors brewing facility at Golden, Colorado is now available. The report spotlights the achievement made by Coors in waste reduction, water reuse, and by-product recovery and utilization. The report shows the significant savings that can be realized through a well planned and well executed environmental control and resource conservation program. Through these efforts Coors has realized a savings of more than $1,500,000 in treatment plant capital costs and a savings of nearly $1,500,000 per year in treatment plant operating costs. The success of the Coors environmental control program is due, to a great extent, to the strong support given by William K. Coors and his management sta-f. The process design improvements and in plant ------- changes made by Coors to reuse water, reduce waste loads and recover by-products are directly applicable to other breweries as well as other food processing industries. To order your copy of this capsule report, use the order blank on the back page. NEW MUNICIPAL SEMINAR PUBLICATIONS AVAILABLE Three new Technology Transfer municipal seminar publications have been published and are now available for distribution. These publications include material developed for the design seminar program and have been used throughout the country. The new seminar publications, which may be ordered by using the request form at the rear of this newsletter, include the following: "Flow Equalization" by Metcalf & Eddy Engineers (Stanley Elkerton, primary author). This publication includes determination of equalization require- ments, design and construction procedures, equalization impact on other treatment compo- nents, costs, and four selected case histories. "Wastewater Filtration" by John Cleasby and Robert Baumann. This publication includes most aspects of filter design including filter configurations, methods of flow control, backwash- ing requirements, headloss development, and selection of filtration rates. "Physical-Chemical Nitrogen Removal" by Culp Wesner, and Culp (Gordon Culp primary author). Included in this publication are design considerations for the three feasible physical-chem- ical methods of nitrogen removal, i.e. selective ion Physical-Chemical Nitrogen Removal Wastewater I nitration I Design Consideratons _ Flow Equalization EmSxjnology BttTfiCirnatogy Tansfcf Seminar Pifck-atian exchange, ammonia stripping, and break point chlorination. Chapters include information on typical design criteria, pilot testing, case histories, costs, and basic comparison of the three processes. MUNICIPAL DESIGN SEMINARS Five additional Technology Transfer municipal design seminars have been conducted in various areas of the country since publication of the last newsletter. These were presented in Newark, New Jersey, March 13-15; San Juan, Puerto Rico, April 8-10; Orlando, Florida, May 7-9; Seattle, Washington, May 21-22, and Boston, Massachusetts, September 10-11. The Newark, N.J. seminar included technical sessions on nitrogen control, upgrading existing wastewater treatment plants, and combined sewer overflows. The nitrogen control session was especially well received with Dr. Clair Sawyer covering biological nitrification and denitrification and Mr. Gordon Culp covering physical-chemical nitrogen removal. They were assisted by Mr. Don Ehreth of the EPA Office of R&D. The San Juan, P.R. seminar included technical sessions on sludge treatment and disposal and upgrading existing trickling filter plants. In addition to the technical session, a general first day session covered the EPA municipal construction program, construction design guidelines and EPA regional grants program and procedures. EPA speakers at this session included Mr. Harold Cahill arid Mr. Charles Sutfin of the Office of Water Programs Operations, and Mr. Rocco Ricci of EPA Region I. This seminar was held with the cooperation of the ------- Attendees of the Orlando, Florida, Seminar. Puerto Rico Environmental Quality Board and the Puerto Rico Aqueduct and Sewer Authority. The Orlando, Fla. seminar included sessions on oxygen aeration, nitrogen control and upgrading existing treatment facilities. The opening morning general session included discussions of user charges, construction guidelines, and municipal permits. The Seattle, Wash, seminar featured two full day sessions on sludge treatment and disposal and infiltration/inflow control. The sludge session featured three of the key individuals involved in preparation of the forthcoming Technology Transfer sludge design manual (see story on 1st page); Dr. Jim Smith of the EPA National Environmental Research Center, Cincinnati; Mr. Jack Harrison of Black, Crow, and Eidness Engrs; and Mr. Gordon Culp of CWC Consultants. The Boston, Mass. seminar featured the first full day nitrogen control session conducted at a T.T. seminar with presentations by Dr. Clair Sawyer, Dr. Denny Parker, Gordon Culp, Don Ehreth and Ed Barth. Technical sessions were also conducted on physical-chemical treatment and phosphorus removal. Key presentations by other speakers at the above seminars were given by Dr. Denny Parker and Warren Uhte, Brown and Caldwell; Dr. Bob Baumann and Dr. Jack Cleasby, Iowa State University; Charles Hansen, Envirex; James Laughlin, Shimek, Roming, Jacobs & Finklea; Ariel Thomas, Metcalf & Eddy; Curt McDowell, Air Products; Mike Miller, Union Carbide; Bob Pfefferle and Tom Clark, American Consulting Service; and Jon Dyer, Ed Ba'th, Dick Field and Jesse Cohen from the EPA R&D staff. SEMINAR SERIES POLLUTION ABATEMENT IN METAL FINISHING FACILITIES The sixth in a series of Technology Transfer seminars on "Upg-ading Metal Finishing Facilities to Reduce Pollution" was held in Chicago, Illinois on May 7-8, 1974. Tne first session of the seminar featured a welcome address by Francis T. Mayo, Administrator for EPA's Region V, and an acdress by Simon P. Gary of the American E ectroplate's Society on the impact of the Water Pol.ution Control Act on the plating industry. Following these addresses, Quentin H. Pickering of the EPA Newtown Fish Toxicology Station gave c presentation on the effects of Heavy Metals on the Aquatic Environment. The first majc technical sessions covering In Process Pollution Abatement was presented by Alan E. Olsen of Oxy Metal Finishing and Ed Hanf of the Culcote Company. This session covered in-plant water reduction, waste load reduction, spill prevention and control, and air emission control. The sessions on Waste Treatment Systems was presented by Dr. Leslie E. Lancy and Fred Steward of Lancy Laboratories. This session included a review of the proven waste treatment alternatives as well as a presentation by Dr. Lancy on Liquid-Solid Separation Soiids Concentration and Sludge Disposal. The final session featured a presentation on Optimum Financial Strategy by Charles R. Marshall of J. A. Commins and Assoc ates and a review of the EPA Demonstration Grant Program by John Ciancia of the Edison Water Qua ity Laboratory. In this ------- session John Ciancia covered the status of emerging technology for treatment of metal finishing wastes. POLLUTION CONTROL SEMINAR FOR THE SEAFOOD INDUSTRY Technology Transfer in cooperation with the National Fisheries Institute and the National Canners Association held its first two seminars for the seafood processing industry entitled "Up- grading Seafood Processing Facilities to Reduce Pollution" in New Orleans, La. on May 5-6,1974, and in Seattle, Washington on April 2-3, 1974. The seminars featured addresses by Roy Martin of the National Fisheries Institute and Allen Katsuyama of the National Canners Association. The emphasis for the two-day seminars was on the sessions concerning In-Plant Control of Wastes and Waste Treatment Systems. The session on In-Plant Control featured Dr. George Piggott of the University of Washington's Institute for Food Science. The session on waste treatment featured Michael Soderquist of Environmental Associates, Inc. The treatment session included informative presentations on the latest progress in waste treatment demonstration projects, presented by Fred G. Claggett of Canada's Envrionmental Protection Service, A. Frank Mauldin of Dorminique, Szabo and Associates, and Irwin F. Snyder of Carborundum Envrionmental Systems, Inc. The seafood processing industry was represented by Roy Martin of the National Fisheries Institute in his talk on Future Considerations of Seafood Technology, and by Allen Katsuyama of the National Canners Association in his talk on Effective Government-Industry Relationships to Control Pollution. The final session of the seminars featured presentations on Optimum Financing Strategy by Charles R. Marshall of J. A. Commins and Associates, and a discussion on the EPA Demonstration Grant Program by Kenneth Dostal and Harold Thompson of the EPA Waste Treatment Research Program in Corvallis, Oregon. MONITORING AND TOXIC SUBSTANCES CONTROL SEMINARS Technology Transfer held its first seminars for industry on Monitoring Industrial Wastewater and Toxic Substances Control in Atlanta, Georgia on April 18 and 19, 1974. The Monitoring Seminar, attended by 300 plant managers, featured a welcome address by John C. White, EPA Deputy Regional Administrator. The morning session of the seminar covered EPA regulatory policy with regard to the monitoring requirements of PL 92-500. Florida, Kentucky, Audience at Technology Transfer Monitoring Seminar held in Atlanta, Georgia. ------- Asa Foster, Technology Transfer Chairman for Region IV, acdresses Monitoring Seminar in Atlanta. Seated from left to right are: Wesley Eckenfelder, of Aware, Inc., and Walter Zabban, of Chester Engineers. Georgia, Mississippi, North Carolina, South Carolina, and Tennessee presented the states' relationship to the Federal Program. The afternoon session offered technical guidance for implementing a monitoring program. Dr. Wesley Eckenfelder of Vanderbilt University and AWARE, Inc. concentrated on an overview of Monitoring Industrial Wastewater. Dr. Phillip Shelly of Hycrospace-Challenger discussed Sampling. The session on Flow Measurement was presented by V c Jelen of the EPA Cincinnati Field Investigation Center. The session on Analytical Quality Control was prepared by Robert Booth of the EPA Cincinnati Methods Development and Quality Assurance Research Laboratory. The final session on In-Process Monitoring was presented by Walter Zabban of Chester Engineers. The Toxic Substances Control seminar was presented on the following day. The first session was cevoted to presenting an overview of the Toxic Substances Provisions of PL 92-500 and EPA's regulatory policy toward Toxic Substances. The final morning session was a presentation on how permits are processed for toxic substance discharges. The second session was designed to present to the participants of the seminar a comprehensive discussion on Guidance for Implementing a Control Program. Charles Sercu of Dow Chemical Company began this session with a talk on Industry's Responsibilities in Toxic Pollutant Effluent Standards. Donald A. Baehl of Union Carbide Corporation prepared the session on Minimizing Toxics in Effluents by Process Design and In-Plant Operating Practices. The next presentation was by Don Hager of Calgon Corporation who discussed Activated Carbon Adsorption of Aldrin, Diedrin, Charles Sercu of Dow Chemical addresses Atlanta Technology Transfer Seminar on Toxic Substances Control. Enorin, PCB's, DDT and Toxaphere. The session on the Control of Cadmium and Cyanide was prepared by Alan E. Olsen of OXY Metal Finishing. Control of Benzidene was the subject of the next session by Thomas Kopp of EPA's Office of Toxic Substances. Dr. Lloyd Falk 0" DuPont Corporation completed the seminar with a presentation on Dispersion Techniques. NEW TECHNOLOGY TRANSFER MOTION PICTURE AVAILABLE— "THE SEATTLE METRO STORY" Another motion picture is now available through :he Technology Transfer Program. The 28 minute, 16 mm color sound film depicts the development of Seattle, Washington METRO interceplor system and treatment facilities and their role in abating pollution of Puget Sound and Lake Washington. The film features the phosphorus removal facilities at the Rentin treatment plant; computer control of combined flew overflows in the interceptor system; use of sludge from the plant centrifuges as landfill; and development and formation of the VlETRO itself. The film was made possible by the cooperation and efforts of the Seattle METRO staff and the EPA Region X staff in Seattle. Requests for loan of this film, and other Technology Transfer films listed on the request form at the rear of this newsletter, may be made to the appropriate Technology Transfer Regional Chair- men also listed at the rear of this publication. ------- «¦- 1eCH|\|QLOGV Let: to right: Dennis Cannon, Paul Minor and Jim Truett of the Technology Transfer Staff participating in the WWEMA Confer- ence TECHNOLOGY TRANSFER PARTICIPATES IN WWEMA CONFERENCE AND EXPOSITION Technology Transfer participated in the Waste Water Equipment Manufacturers Association (WWEMA) annual meeting ir Detroit on April 1-4 1974, with a presentation of Technology Development by Paul Minor and an exhibit featuring the industrial seminar publications for the meat packing, metal finishing and poultry industries, the industrial technical capsule reports and the Handbook on Monitoring Indjstrial Wastewater. FUTURE MONITORING SEMINARS A Monitoring Industrial Wastewater Seminar was held on April 18, 1974, in Atlanta. See article on page 5 of this Newsletter. This seminar was an overwhelming success as measured by the attendance, and feedback obtained since the seminar. Technology Transfer is planning to present 10 additional Monitoring seminars - ore in each EPA Region - during this fiscal year. Final dates and locations have not yet been finalized. I ¦ you are interested in attending one of these seminars, contact your Regional Technology Transfer Chairman listed in this Fact Sheet. TEXTILE SEMINAR PUBLICATIONS FEATURED AT THE INTERNATIONAL TEXTILE EXPOSITION Technology Transfer will provide an exhibit at the International Textile Exposition (ITEX) in Greenville, South Carolina on October 21-25,1974. The exhibit will feature the distribution of a two part publication series on "Upgrading Textile Operations to Reduce Pollution" which were developed for the Technology Transfer seminar for the textile industry. The publications cover "In-Plant Control of Pollution" and "Wastewater Treatment Systems". Volume one on In-Plant Control was prepared under the direction of the Institute of Textile Technology by experts within the Textile industry. Volume two on waste treatment was prepared by Metcalf & Eddy Inc., consulting engineers. Asa B. Foster Jr., Technology Transfer Chairman for EPA Region IV in Atlanta and several Regional representatives will participate in the ITEX exhibition. For your copy of these publications, use the order form on the back of this newsletter. FLOW EQUALIZATION* GENERAL The primary objective of flow-equalization basins for municipal wastewater plants is simply to dampen the diurnal flow variation, and thus achieve a constant or nearly constant flow rate through the downstream treatment processes. A desirable secondary objective is to dampen the concentration and mass flow of wastewater constituents by blending the wastewater in the equalization basin. This results in a more uniform loading of organics, nutrients, and other suspended and dissolved constituents to subsequent processes. Through achieving these objectives, flow equalization can significantly improve the performance of an existing treatment facility, and is a useful upgrading technique. In the case of new plant design, flow equalization can reduce the required size of downstream facilities. Variations Of Flow Equalization Equalization of municipal wastewater flows may be divided into three broad categories: •Equalization of dry weather flows •Equalization of wet weather flows from separate sanitary sewers •Equalization of combined storm and sanitary wastewater This discussion is primarily concerned with equalization of dry weather flows. This procedure *Extracted from "Flow Equalization" prepared for the EPA Technology Transfer Seminar Publication Series. Use the form at the rear of this newsletter for a copy of the complete publication. ------- provides a technique for achieving normal operation of a treatment plant under near ideal loading conditions. Its relatively low cost makes it attractive: for upgrading an overloaded plant. Although the use of influent sewers for equalization should not be ignored, the most positive and effective means to maximize the benefits possible with equalization is through the use of specially designed equalization basins. These basins should normally be located near the head end of the treatment works, preferably downstream of pretreatment facilities and mixing must be provided to keep the basins aerobic and prevent solids deposition. It is sometimes desirable to locate the equalization basin at strategic locations within the collection system. This offers the added advantage of economically relieving trunk sewer overload during peak flow periods.1 However, it does result in the need for a pumpjng facility and therefore is best located where a need for pumping already exists. Equalization basins may be desired as either in-line or side-line units. In the in-line design all the flow passes through the equalization basin. This, results in significant concentration and mass flow damping. In the side-line design only that amount of flow above the daily average is diverted through the equalization basin. This scheme minimizes pumping requirements at the expense of less effective concentration damping. For new construction and for upgrading large plants, it is desirable to,construct compartmental- ized or multiple basins. This feature will allow the flexibility to dewater a portion of the facility for maintenance or equipment repair while still providing some flow equalization. Where a basin is designed for storage and equalization of wet weather flows, compartmentalized tanks will allow the utilization of a portion of. the basin for dry weather flow equalization. Single basin installations may be used for upgrading small plants, but must have the provision to be dewatered while maintaining complete treatment. This will require a bypass line around the basin to allow the downstream portion of the plant to operate unequalized when the flow equalization facility is out of service. Impact On Primary Settling The most beneficial impact on primary settling is the reduction of peak, overflow rates resulting in improved performance and a more uniform primary effluent quality. Flow equalization permits the sizing of new clarifiers based on equalized flow -rates rather than peak rates. In an existing primary clarifier that is hydraulically overloaded during periods of peak diurnal flow, equalization can reduce the maximum overflow rate to an acceptable level. A constant influent feed rate also avoids hydraulic disruptions in the clarifier created by sudden flow changes, especially those caused by additional wastewater lift pumps suddenly coming on line. LaGregaand Keenan2 investigated the effect of flow equalization at the 1.8 mgd Newark, NJ., Wastewater Treatment Plant. An existing aeration tank was temporarily converted to an equalization basin. They compared the performance of primary settling under marginal operating conditions, with and without equalization. The results are show in Table 1. It has been demonstrated3,4 that preaeration can significantly improve primary settling. Roe3 concluded that preaeration perflocculates sus- pended solids (SS) thereby improving their settling characteristics. Indications are that this benefit may be realized by aerated equalization basins. This benefit may be diminished when the equalized flow is centrifugally pumped to the primary clarifier due to the shearing of the floe. Impact On Biological Treatment Table - Effect of flow equalization on primary settling, Newark, N.Y. Item Normalflow Equalized flow Primary influent SS, mg/l 136.7 128 Primary effluent SS, mg/l 105.4 . 68 . SS removal in'primaries, percent . 23 47 Note.-Average flow slightly higher in unequalized portion of study. As contrasted to primary treatment or other mainly physical processes where concentration damping is of minor benefit, biological treatment performance can benefit significantly from both concentration damping and flow- smoothing. Concentration damping can protect biological processes from.upset or failure from shock loading, of toxic or treatment inhibiting side-line basins for biological treatment applications. Improvement effluent quality due to stabilized mass loading of BOD on biological systems treating normal domestic wastes has not been adequately demonstrated to date. It is expected that the effect will be significant where diurnal fluctuations in I organic mass loadings are extreme. This situation ' may arise at a wastewater treatment plant receiving a high-strength industrial flow of short duration. Damping of flow and mass loading will also improve aeration tank performance where aeration equipment is marginal or inadequate in satisfying peak diurnal-loading oxygen demands.5 The optimum pH for bacterial growth lies between 6.5 and 7.5. In-line flow equalization can provide an effective means for maintaining a stabilized pH within this range. Flow smoothing can be expected to improve final settling even more so than primary settling. In the activated-sludge process, flow equalization has the added benefit of stabilizing the solids loading on the final clarifier. This has two ramifications: •The mixed-liquor suspended solids (MLSS) concentration can be incareased thereby decreasing the food-to-mass ratio (F/M) and increasing the solids retention time (SRT). This may result in an increased level of nitrification, and a decrease in biological sludge production. It may also improve the performance of a system ------- operating at an excessively high daily peak F/M. •Diurnal fluctuations in the sludge blanket level will be reduced. This reduces the potential for solids being drawn over the weir by the higher velocities in the zone of the effluent weirs. Miscellaneous Benefits In chemical coagulation and precipitation systems using iron aluminum salts, the quantity of chemical coagulant required as proportional to the mass of material to be precipitated. Damping of mass loadings with in-line equalization will improve chemical feed control and process reliability, and many reduce instrumentation complexity and costs. Flow smoothing will reduce the surface area required and enhance the performance of tertiary filters. A constant feed rate will lead to more uniform solids loadings and filtration cycles. The equalization basin provides an excellent point of return for recycled concentrated waste streams such as digester supernatent, sludge-dewatering filtrated, and polishing-filter backwash. Some biochemical oxygen demand (BOD) reduction is likely to occur in an aerated equalization basin. A 10-to-20-percent reduction has been suggested for an in-line basin equalizing raw wastewater. However, the degree of reduction will depend upon the detention time in the basin, the aeration provided, wastewater temperature, and other factors. For an existing treatment plant, a simple series of oxygen uptake studies on a representative sample of wastewater can determine the BOD reduction that will occur. Roe3 observed that preaeration may improve the treatability of raw wastewater by creating a positive oxidation-reduction potential, thereby reducing the degree of oxidation required in subsequent stages of treatment. Determination Of Equalization Requirements The design of an equalization basin requires the evaluation and selections of a number of features as follows: • In-line, versus side-line basins • Basin volume • Degree of compartmentalization • Type of construction-earthen, concrete, or steel •Aeration and mixing equipment • Pumping and control concept • Location in treatment system The design decisions must be based on the nature and extent of the treatment processes used, the benefits desired, and local site conditions and constraints. It may not be necessary to equalize the entire influent flow where high flow or concentration variations can be attributed to one source, such as an industry. In these cases the desired benefits can be achieved by simply equalizing the industrial flow. This can be accomplished through construction of an equalization basin at the industrial site or through in-house industrial process modifications to effect and equalized wastewater discharge. Determination Of Required Volume BOD m«* loading Puk: mr*9* • 1.97 Minimum: *v*rage*0.M 14.SS BOD m«»» loading TIME OF DAY Figure 1. Raw Wastewater (low and BOD variation before equalization. Two methods are available for computing equalization volume requirements. One procedure is based on the characteristic diurnal flow pattern. In this case, the function of the basin is to store flows in excess of the average daily flow and to discharge them at times when the flow is less than the average. The required volume can be determined graphically through the construction of a hydrograph. The second procedure is based upon the mass loading pattern of a particular constituent. This method computes the volume required to dampen mass loading variations to within a preset acceptable range.6-7 Since the prime objective of flow equalization in wastewater treatment is to equalize flow, the determination of equalization volume should be based on the hydrograph. Once the volume has been determined for flow smoothing, the effect on concentration and mass load damping can be estimated. The required volumes for side-line and in-line basins will be identical. The hydrograph procedure is discussed below. The first step in design involves the establishment of a diurnal flow pattern. Whenever possible, this should be based upon actual plant data. It is important to note that the diurnal pattern will vary from day to day, especially from weekday to weekend, and also from month to month. The pattern selected must yield a large enough basin design to effectively equalize any reasonable dry weather diurnal flow. Figure 1 depicts a typical diurnal flow pattern. The average flow rate is 4.3 mgd. For purpose of this example, the average flow is used as the desired flow rate out of the equalization basin. The diurnal peak and minimum flow rate for this example are 1.7 and 0.45 times the average, respectively. The next step involves the actual construction of the hydrograph. The hydrograph for this example is shown on figure 2. The inflow mass diagram is plotted first. To do this, the hourly diurnal flows are converted to equivalent hourly volumes, and accumulated over the 24-hour day. A line is then drawn from the origin to the end point on the inflow-mass diagram. The slope of this line actually represents the average flow for the day. Enough tank volume must be provided to accumulate flows above the equalized flow rate. This normally requires a volume equivalent to 10 to 20 percent of the average daily dry weather to the ------- average flow are shown as lines A and B on figure 2. The required volume is represented by the vertical distance between these two lines. In this illustration, the required volume for equalization is 740,000 gallons, which represents approximately 17 percent of the average daily flow. //' A \ /ft /// >/// /// /// J ¦ //' / - //1 / jy ' / /t / / f /*"" B / / / I f / - / / / // / / 7/ / / // ' / /1 f / Requited equalisation / J / / volume. 740,000 gallons / // / / /J / - 7- -H 7 /'If ' / / f / / / / / / / / / / ' / / / / Inflow mass diagram / / / • / / f t / / / / / / / Average ftow. 4.3 mgd / / / / f / / / / / / / / ' // / / // / ' // / / // / / / / • f / / fr / f i / i i i i1 12 2 4 6 8 10 12 2 4 6 8 10 12 Midnight Noon Midnight TIME OF DAY Figure 2. Hydrograph for typical diurnal (low. The actual equalization-basin volume must be greater than that obtained with the hydrograph for several reasons, including Continuous operation of aeration and mixing equipment will not allow complete drawdown. • Volume must be provided to accommodate anticipated concentrated plant recycle streams. • Some contingency should be provided for unforeseen changes in diurnal flow. The final volume selected should include adequate consideration of the conditions listed above and will also depend on the basin geometry. For the example presented herein, a basin volume of approximately 1 million gallons is adequate. References JC. N. Click, "The Feasibility of Flow Smoothing Stations in Municipal Sewage System," USEPA Project No. 11010 FDI, Contract No. 14-12-935, Aug. 1972. 2M. D. LaGrega and J. D. Keenan, "Effects of Equalizing Sewage Flow," presented at 45th Annual Conference of the Water Pollution Control Federation, Atlanta, Ga., Oct. 1972. 3F. C. Roe, "Preaeration and Air Flocculation," Sewage Works J., 23, No. 2. 127-140, 1951. 4H. F. Seifel and E. R. Baumann, "Effect of Preaeration on the Primary Treatment of Sewage,: J. Water Pollut. Cont. Fed., 33 No. 4, 339-355, 1961. 5A. G. Boon and D. R. Burgess, "Effects of Diurnal Variations in Flow of Settled Sewage on the Performance of High Rate Activated-Sludge Plants," Water Pollution Cont., 493-522, 1972. 6 P. R. Bradley and J. Y. Oldshue, "The Role of Mixing in Equalization," presented at 45th Annual Conference of the Water Pollution Control Federation, Atlanta, Ga., Oct. 1972. 7A. T. Wallace, "Analysis of Equalization Basins," J. Sanit. Eng. Div., ASCE, SA6, 1161-1171, 1968. Where To Get Further Information In order to get details on items appearing in this publication, or any other aspects of the Technology Transfer Program, contact your EPA Regional Technology Trans- fer Committee Chairman from the list below: REGION CHAIRMAN I Lester Sutton II Robert Olson III Albert Montague IV' Asa B. Foster, Jr. V Clifford Risley ADDRESS Environmental Protection Agency John F. Kennedy Federal Building Room 2304 Boston, Massachusetts 02203 617 223-2226 [Maine, NX, Vt, Mass. R.U Conn;] Environmental Protection Agency 26 Federal Plaza New York. New York 10017 212 264-1867 [N.Y., NJ., P.R., V.I.] Environmental Protection Agency 6th & Walnut Streets Philadelphia. Pennsylvania 19106 215 597-9856 [Pa. W.Va. Md. Dei, D.C„ Va.] Environmental Protection Agency Suite 300 1421 Peachtree Street, N.E. Atlanta, Georgia 30309 404 526-3454 [N.C„ SC. Kyn Tenn„ Ga., Ala., Miss., Fla.] Environmental Protection Agency 1 N. Wacker Drive Chicago, Illinois 60606 312 353-5756 [Mich., WiSn Minn., IIL, Ind., Ohio] REGION CHAIRMAN VI Mildred Smith VII John Coakley VIII Russell Fitch IX Frank Covington X ' John Osborn ADDRESS Environmental Protection Agency 1600 Patterson Street, Suite 1100 Dallas, Texas 75201 214 7491461 [Texas, Okla„ Ark., La., N. Mex.] Environmental Protection Agency 1735 Baltimore Avenue Kansas City, Missouri 64108 816 374-5971 [Kansas, Nebr., Iowa, Mo.] Environmental Protection Agency 1860 Lincoln Street Denver, Colorado 80203 303 837-3849-837-3691 [Colo., Mont, Wyo., Utah, N.D. S.D.] Environmental Protection Agency 100 California Street < San Frantisco, Calif. 94111 415 556-0218 [Calif., Ariz., Nev., Hawaii] * Environmental Protection Agency 1200 6th Avenue Seattle, Washington 98101 206 442-1296 [Wash. Ore. Idaho, Alaska] ------- REQUEST FOR TECHNOLOGY TRANSFER MATERIAL Please send me the following publications at no charge. (Check appropriate boxes) The publications Listed on this form are the only ones available through the Office of Technology Transfer. PROCESS DESIGN MANUALS ~ Phosphorus Removal 1001 ~ Carbon Adsorption 1002 ~ Suspended Solids Removal 1003 G Upgrading Existing Wastewater Treatment Plants 1004 ~ Sulfide Control in Sanitary Sewerage Systems 1005 G Sludge Treatment and Disposal 1006 TECHNICAL CAPSULE REPORTS G Recycling Zinc in Viscose Rayon Plants 2001 G Color Removal from Kraft Pulping Effluent by Lime Addition 2002 G Pollution Abatement in a Copper Wire Mill 2003 G First Interim Report on EPA Alkali SO2 Scrubbing Test Facility 2004 G Dry Caustic Peeling of Peaches 2005 l~l Pollution Abatement in a Brewing Facility 2006 INDUSTRIAL SEMINAR PUBLICATIONS G Upgrading Poultry Processing Facilities to Reduce Pollution (3 Vols.) 3001 G Upgrading Metal Finishing Facilities to Reduce Pollution (2 Vols.) 3002 G Upgrading Meat Packing Facilities to Reduce Pollution (3 Vols.) 3003 G Upgrading Textile Operations to Reduce Pollution (2 Vols.) . 3004 MUNICIPAL SEMINAR PUBLICATIONS G Upgrading Lagoons 4001 O Physical-Chemical Treatment 4002 G Oxygen Activated Sludge 4003 G Nitrification/Denitrification 4004 G Upgrading Existing Wastewater Treatment Facilities-Case Histories 4005 • G Flow Equalization 4006 • G Wastewater Filtration 4007 • G Physical-Chemical Nitrogen Removal 4008 BROCHURES G Physical-Chemical Treatment 5001 G Phosphorus Removal 5002 G Upgrading Existing Wastewater Treatment Plants 5003 G Carbon Adsorption 5004 G Oxygen Aeration 5005 G Nitrogen Control 5006 G Seattle, Washington METRO 5007 G Wastewater Purification at Lake Tahoe 5008 G Indian Creek Reservoir 5009 G Richardson, Texas 5010 HANDBOOKS G Analytical Quality Control in Water and Wastewater Laboratories 6001 G Monitoring Industrial Wastewater 6002 Publications listed for first time For the following audio-visual material, please contact your Regional Technology Transfer Chairman. (See listing) MOTION PICTURES (16mm sound) VIDEOTAPES Richardson Texas Project — Title: "Somebody around here must be doing something good." (15 min.) Phosphorus Removal (5 min.) Water Quality Management, Alameda Creek, Calif. — Title: "The Water Plan" (28K min.) Carbon Adsorption (40 min.) Upgrading Activated Sludge Treatment Plants (40 min.) The Seattle METRO Story (28 min.) If you are not currently on the mailing list for this Technology Transfer Newsletter, do you want to be added? G YES GNO Name ¦ Employer '¦ Title Street Phone City " State Zia NOTE: Tear this sheet out and forward to Technology Transfer, U.S. Environmental Protection Agency, Washington, D.C. 20460. ------- ENVIRONMENTAL PROTECTION AGENCY OFFICIAL BUSINESS POSTAGE AND FEES PAID PENALTY FOR PRIVATE USE. $300 ENVIRONMENTAL PROTECTION AGENCY LOU TILLEY library region V 1 N VJACKER DR A[] CHICAGO IL 60606 ------- |