OFFICE OF ENFORCEMENT EPA-330/1-79-002 Disposal Alternatives For Tuna Cannery Dissolved Flotation Sludge, Stickwater, And Press Liquor American Samoa NATIONAL ENFORCEMENT INVESTIGATIONS CENTER DENVER. COLORADO ^t0 S7^ AND REGION IX SAN FRANCISCO MARCH 1979 ------- Environmental Protection Agency Office of Enforcement EPA-330/1-79-002 DISPOSAL ALTERNATIVES FOR TUNA CANNERY DISSOLVED AIR FLOTATION SLUDGE, STICKWATER, AND PRESS LIQUOR AMERICAN SAMOA Barrett E. Benson March 1979 National Enforcement Investigations Center - Denver and Region IX - San Francisco ------- • CONTENTS I. INTRODUCTION . II. SUMMARY AND CONCLUSIONS III. DISPOSAL OF SOLID WASTES AND RESIDUAL MATTER . CURRENT DISPOSAL METHODS PROBLEMS ASSOCIATED WITH CURRENT DISPOSAL METHODS IV. DISPOSAL ALTERNATIVES SEGREGATION OF WASTEWATER STREAMS DISPOSAL ALTERNATIVES RESTORATION OF EXISTING DISPOSAL SITES V. ODOR SOURCES AND CONTROL AT THE TUNA CANNERIES ODOR SOURCES ODOR CONTROL APPENDIX APPENDIX A . . . 33 FIGURES 1 Pago Pago Harbor, American Samoa 2 Tutuila Island, American Samoa 3 Star-Kist Samoa, Inc. Process, Flow and.Wastewater Treatment 4 Process Sequence and Wastewater Flow Van Camp Seafood 5 Wastewater Collection Channel Precooker Area - Van Camp . . 6 Schematic of Wastewater Drainage Precooker Area - Star Kist 7 Ocean Disposal Location Tuna DAF Sludge and Stickwater . . 13 16 16 19 28 30 30 30 .2 .3 10 11 • 18 20 24 ------- • I. INTRODUCTION From June 19 to July 18, 1978, personnel from the National En- forcement Investigations Center (NEIC) evaluated disposal alterna- tives for the sludge generated in the dissolved air flotation (OAF) wastewater treatment systems at the two tuna canneries in American Samoa. The Van Camp Sea Food Company, a division of the Raison Purina Company, and Star-Kist Samoa, Inc., a subsidiary of the H. J. Heinz Company, each operate canning facilities on the north shore of Pago Pago harbor [ Figure 1]. Disposal of solid waste and DAF sludge is a difficult problem in Samoa because of limited land availability and geological conditions. American Samoa, situated in the South Pacific ocean, about 3,540 km (2,200 mi) southwest of the Hawaiian Islands, consists of six islands with a total land area of 197 square kilometers (76 sq mi). The in- habited islands include Tutuila, Tau, Olosega, Ofu, and Aunu t u. The main island of Tutuila [ Figure 2] with an area of 137 square kilometers (53 sq ml) rises steeply above deep inlets, the most notable of which is Pago Pago harbor. The topography is mainly mountainous and most of the villages are located on the coast line. Rainfall varies from 100 to 300 inches, but porous soils and rocks make water supplies unreliable. The population of American Samoa in 1970 was 27,000; of these 21,000 lived on Tutuilalsland.* The two canneries currently dispose of the DAF sludge in open pits on leased land in semi-remote areas of Tutuila Island. Star-Kist’s * The New Encyclopaedia Britannica, Volume 16, 15th Edition, 1977. ------- STAR -K 1ST MAR INE POWER STATIO . 0 Figure i Pago Pago Harbor , American Samoa ------- 0 MUNIC IPA 0 AUNU’U ISLANZ A FUNA STAR-K 1ST SLUDGE DISPOSAL STEPS POINT TULEI WWTP W W T P OUTFALL VAN CAMP SLUDGE DISPOSAL Figure 2 Tutuila Island, American Samoa ------- 4 disposal site is located in the area of Matauloa Ridge, about 0.8 km (0.5 mi) from Steps Point [ Figure 2]. The disposal pits have been excavated on the edge of the ridge. The earthen sides of one pit failed in January 1979 and some of the sludge spilled into Larsen Bay. The sludge from Van Camp is placed in ravines near the airport, adjacent to the community of Tafuna. Because the disposal site is inland, the probability of the sludge flowing into the ocean is small, however, the disposal area lies over the freshwater aquifier used as drinking water for the communities served by the Government of American Samoa (GAS) water system. The Environmental Quality Commission (EQC), the Governor’s office, and the health department have received numerous complaints concerning odors and vectors at the disposal areas, and the transport of the sludge through densly populated areas. The odors are obnoxious and are detectable several miles from the disposal areas. The EQC has ordered the canneries to initiate procedures to eliminate the disposal problems by alternative methods. Methods suggested by the EQC include disposal through the Tafuna primary wastewater treatment plant ocean outfall, barging to sea forocean disposal, and digestion and dewater- ing the sludge followed by land disposal. Due to the numerous and increasing citizen complaints, the prob- lems of decreasing land availability, and the need for adequate and proper disposal, Region IX of the Environmental Protection Agency (EPA) requested NEIC to evaluate disposal alternatives for the OAF sludge, cannery stickwater and press liquor. (Stickwater or cooker juice is formed in the precooking process where live steam contacts the tuna and the res u1ting wastewater contains high concentrations of organics. Press liquor is the wastewater resulting from the compac- tion of recovered fish waste solids in the fish meal process. The stickwater and press liquors are normally processed in a solubles facility at most tuna plants, however, in Samoa they are discharged ------- 5 to the OAF treatment systems). Subsequent to the investigaUon in Samoa, Region IX requested that NEIC eva1uate the odor problems asso- ciated with canneries. This report summarizes the current disposal methods used by the canneries, odor sources, and their associated problems. Disposal al- ternatives which can be used in Samoa under the present constraints were evaluated and are presented. The determination of volumes and constituents of the wastes and the selection of disposal sites were beyond the scope of this investigation. ------- II. SUMMARY AND CONCLUSIONS NEIC personnel conducted detailed in-plant investigations of the wastewater sources, treatment systems, and operating procedures of the two canneries. Meetings and discussions were held with cannery management and Government of American Samoa personnel to ascertain the magnitude of the problem and possible alternatives. Disposal sites were visited to determine the adequacy of disposal. The best method for DAF sludge disposal in Samoa utilizes the most available and abundant resource, the ocean. The land is a limi— ted resource and should not be used for sludge disposal; the ocean in this remote sector of the world offers a means to dispose of a non- hazardous and non-toxic waste which will not unreasonably degrade or endanger human health, welfare, or marine environment. The sludge should be barged to sea for disposal. Stickwater and press liquor wastewater streams can be segregated from the other process waste- waters and could also be barged to sea with the sludge. This would reduce operating costs of the wastewater treatment facilities and would also reduce the pollutant load discharged to the Pago Pago har- bor. However, the disposal cost for sludge will probably increase over the current land disposal method. Ships and barges are available in Samoa for this disposal method. An alternative land-based.disposal site would be required for the periods when the weather prevented ocean disposal and tank storage capacity on the cannery sites is exhaus- ted. An alternative to ocean disposal is to dewater, deodorize, and stabilize the sludge prior to landfilling. Due to vectors, odors, safety, etc. , the sludge must be backcovered daily, thus requiring heavy equipment. Operating costs could be minimized by operating a ------- 7 disposal site as a joint venture. If there is sufficient land avai1 able, the sludge could be mixed with the commercial and residential refuse at the municipal landfill, as is done in southern California landfills, thus eliminating the need for heavy equipment at a separate site. However, land disposal is discouraged as a disposal alternative except in cases of emergencies because eventually available sites will be filled and ocean disposal will have to be used. The land sites should be reserved for material which cannot be barged to sea. Because of potential environmental damages, the existing disposal sites should be reclaimed by removing the sludge and contouring the areas to their natural state. The reclaimed sludge could be barged to sea for disposal or placed in an approved disposal site if ocean disposal is not implemented. Odor control at the canneries will be expensive because the tech- nology did not exist when the facilities were built. Major sources of odors include the precookers, fish meal driers, and wastewater treatment facilities. Technology for control includes collecting the air emissions from the precookers and driers and scrubbing with limed sea water, chemical oxidation with chlorine, and incineration. The emissions from the wastewater treatment units can be controlled by the use of masking agents or chemical oxidation. ------- III. DISPOSAL OF SOLID WASTES AND RESIDUAL MATTER A high degree of product recovery is practiced in the tuna can- ning industry. According to the Development Document* studies of nine tuna plants, final waste represented about 1% of the raw input. Food recovery averaged 45%, the rest of the tuna meat and scraps were processed into pet food, fish meal and a solubles product. Of the nine tuna canneries investigated, only one did not have a solubles operation. This cannery separated the stickwater and press liquor from other process wastewater streams and barged these high strength wastewaters to sea for disposal. The two canneries in Samoa do not have solubles processes but, instead of separating the stick-water and press liquors for ocean disposal, they are discharged to the DAF treatment system. The cannery solid wastes currently subject to disposal are the fish solids retained on the screens in the waste- water collection systems, the OAF cell sludge, and refuse material. CURRENT DISPOSAL METHODS Screening Wastes Fish solids removed by the screens are not recovered for pro- cessing into fish meal because they also contain grit, dirt,. nails, nuts, bolts, and other debris from the processing areas. Approxi- mately 0.91 m. tons (1 ton)/day of fish solids and refuse material from each cannery are hauled in open bed, cannery-owned trucks to the municipal landfill. * 11 Developnient Document for Effluent Limitations Guidelines and New Source Performance Standards for the Catfish, Crab, Shrimp, and Tuna Segment of the Canned and Preserved Seafood Processing Point Source Catagory” EPA-440/1-74-020-a, June, 1974. ------- 9 The beds of trucks are lined with paper to prevent dripping during transport to the landfill and sprayed with an industrial deodorant, Otaban #5l8B, to reduce odor. The landfill is located near Tafuna [ Figure 21. All refuse collected on the island is deposited in this landfill or in a temporary site on the north side of the island. The temporary site was in operation during the NEIC inspection, but Govern- ment of, American Samoa (GAS) off icals stated that disposal in the temporary site would cease in the near future. Due to the lack of available land, all future disposal would be.in the landfill near lafuna. The landfill is operated only during daylight hours because there are no lights at the site or on the bulldozer usedto backfill. The refuse deposited in the landfill is covered daily. DAF Sludge Each cannery treats its process wastewater prior to discharge to the Pago Pago harbor; the wastewater treatment facilities are similar and differ only in sizes and operating procedures [ Figures 3 and 4]. After in-plant screening to remove coarse solids and debris, the raw wastewater is pumped to the surge tank. Aluminum sulfate (alum) and a polyelectrolyte coagulant aid are added to the wastewater, air is introduced and the wastewater is pressurized before it enters the DAF cell. High concentrations of solids, oil and grease (O/G) and organic material are removed as floating sludge from the DAF cell. The sludge is continuously removed from the cell surface and held in a sludge tank before being hauled to the disposal site. Settled material in the cell is periodically removed to the sludge tank. Storage capacity in the sludge tank is minimal. Each full pro- duction day generates approximately 30 m (8,000 gal) of sludge. At Star-Kist, the sludge is pumped from the sludge tank into a 7.6 m (2,000 gal) tank truck and transported to land leased by Star-Kist in the area of Matauloa Ridge, about 0.8 km (0.5 mi) from Steps Point [ Figure 2]. During the June-July, 1978 inspection, the disposal ------- Salt Liver to Pet Food Line Fish Meal Direct Contact Cooling Water Fish Box Brine Water From Purse Seiners Solids Recycle Valve 001 ——— Flume Water —-- --r- Shipping Land Disposal Polymer Bagging and Palletizing Figure 3, Star-Kist Samoa, Inc. Process Flow and Mastewater Treatment Diagram June 1978 To Landfill Clean Up tiater I- U U) C I - Process ————— Wastes Scraps, Viscera -J ------- Viscera Viscera r 1 “ I 1 Fish Boxes ( w j j j ‘ ] FiSh j _ Conveyor Butcher ‘ Precookers h nderSump Cold Storac FI 2 S!0 4 . .. .. Dock Water verflow Fresh Water Acid Caustic Fresh _ I I I ] I I L1C v I I [ iners F:::::::::::::::::::::t::::: 3 ... ... .1... ,... 1 r L J Roto Li Cooker .. I . ..... iStralner Juice I ______________ __________ I Sunip Sum I L 4__L-Shaped Ut11 • _________ Light Cleanino _______ ___________ Can ________ iieat Iia s I Alum__________ Can Retorts I • I sh ( 10) 1 coollng J ( 13) r 1 I .. [ Tank i ah L 11 _]. a Sea1in (pet food) (1) Air ____ Scrap __________ Pit • ..Sunp __________________ Condenser I I .. . .. . . . _ I I RetenUon I Water — ume . .“. . .rn— - . —U. .. . .- Tank iPolymer ______________ i I _________ lOutfall Desludner piL)J21fl2.I_Cooker team OAF F + Sump L... . ___J i Lsea Water Br1t j ludo .* .4 Sludge lasher Tank 1 L. Storage water bottom ‘-1 ______________ _________________ 0 Continuous Prod t - Trucked to Fish Oil ...J Driçr (21 UC Land Disposal Tanks (2 ) _____________ Water and Wastewater F rmnder I — . — . Scraps, Viscera Figure 4 Process Sequence and Wastewater Flow VanCamp Seafood, American Samoa s ,June-July , 1978 (Fish Meal) -a ------- 12 location consisted of three rectangular basins with the following dimensions: 27 m x 5.1 ni x 3.7 m deep (90 ft x 17 ft x 12 ft); 30 rn x 3.7 m x 3 ni deep (100 ft x 12 ft x 10 ft); and 91 m x 30 rn x 7.6 m deep (300 ft x 100 ft x 25 ft). The two smaller basins had been filled to capacity and the third was almost full. A fourth basin was being constructed, 91 m x 46 m x 7.6 m deep (300 ft x 150 ft x 25 ft) for immediate use. At a rate of sludge production of 30 m 3 /day, there is sufficient capacity for about 1,000 production days. The basins were excavated on the side of the ridge and if overflow occurs as the sludge is discharged into the pits, or during heavy rainfall, or if the earth- en sides of the basins fail, the waste material will flow down into Larsen Bay. The pits are not backcovered. The sludge from the Van Camp OAF cell is hauled in a tank trailer, originally used to transport gasoline to service stations, to a semi- remote disposal area. The disposal site, leased from private land- owners, is near the airport and the Lava Lava golf course and is adja- cent to the community of Tafuna. The Samoa Bible Institute is located within 0.8 km (0.5 ml) of the disposal area. The OAF sludge is dis- charged into ravines, or ravine-like depressions and is not backcovered. Because the disposal site is inland; the probability of the sludge flowing into the ocean is small, however the disposal area lies over the fresh water aquifer used as drinking water for the communities served by the GAS water system. According to GAS personnel, chemical analyses of the groundwater indicate that the aquifer has not been contaminated, but they are concerned that this could occur. Van Camp has backcovered one disposal pit nearest the Bible Institute. An inactive site, between the backcovered site and the active site has not been backcovered. Star-Kist has not backcovered any of its inactive disposal pits. Although the disposal areas are in remote of semi-remote areas, access is not controlled-and a poten- tial hazard to the public exists. ------- 13 PROBLEMS ASSOCIATED WITH CURRENT DISPOSAL METHODS The Environmental Quality Commission, Government of American Samoa, has received numerous complaints regarding odors associated with the operation of the tuna canneries and the disposal of OAF sludge. Similar complaints have also been received at the Govenor’s office. In a May 1978 letter, the Commission advised the personnel at each cannery to immediately increase their efforts to control and reduce the odors associated with the OAF sludge, particularly at the disposal sites. It was suggested by the Commission that additional chemicals such as oxidizing agents (hydrogen peroxide or chlorine dioxide), lime for pH control, and the continued use of deodorants, odor masking compounds and insecticides might be required to assist in the effort. Because of the problems associated with the disposal of raw sludge on land, cannery personnel were also urged to continue efforts in evaluat- ing and implementing alternate sludge handling, treatment and disposal procedures. The commission established December 1, 1978 as the deadline for submitting evidence that an alternative procedure has been selected and that action has been initiated to implement the selected process by January 1, 1979. The Commission delineated the following three alternatives, or a combination of them, which could be implemented to correct the disposal problems. 1. Disposal of raw sludge through the Tafuna sewage treatment plant outfall under a permit form the Environmental Protection Agency. 2. Disposal of raw sludge to marine waters by barging under a permit from the Environmental Protection Agency. 3. Anaerobic or aerobic digestion and dewatering of the sludge followed by land disposal. ------- 14 As a followup of the Commission’s letters, a meeting was held June 22, 1978, at the Star-Kist Samoa office to discuss the problems and alternatives. Representatives of Star-Kist, Van Camp, Government of American Samoa, and EPA were present [ Appendix A]. The sludge disposal problems were defined at the meeting to be: 1. Odors and vector control at the OAF sludge disposal sites 2. Land availability - 3. Transport of the DAF sludge from the canneries to the disposal sites The odors from the Van Camp disposal site near Tafuna are readily detectable at the villages of Pa vaiai and Faleniv (total polulation between 400 and 500). The odors are also detectable at the Community College. Three villages on the sea side of Leone, [ Futiga, Taputimu, and Vailoatai (total population about 500)] have complained about the odors from the Star-Kist disposal pits. The odors are very offensive and, although wind dependent, were always detected by NEIC personnel when in the Tafuna area. Flies, rodents, and mosquitoes are the vectors associated with sludge disposal. There are two mosquito borne diseases on the island, Filariasis and Dengue Fever; the Department of Public Health is trying to control the mosquitos and feels that the disposal sites should be closed and covered as one of the control methods. The GAS also receives numerous complaints about the OAF sludge trucks and the open-bed trucks which haul the refuse and screenings to the municipal landfill. The trucks must pass through Pago Pago on the route to the disposal sites. Although the trucks are washed and deodorized with Otaban at the canneries before each trip, the odors are noticeable during transport. NEIC personnel detected the odors from the Van Camp sludge truck from a distance of approximately 15 m. (50 ft) as it passed through Paga Pago. ------- 15 Both Star-Kist and Van Camp stated that the sludge problem was being investigated at their respective offices in California and that they would try to meet the December response date. However, except for the use of the Tafuna sewage treatment plant outfall, representa- tives from each cannery were not prepared to comment on alternatives being studied in California. Both canneries feel that the outfall is the best solution and disposal could begin immediately. Star-Kist also stated that barging of the sludge was feasible and that several people on the island were interested in providing the service, but require a long-term commitment from the canneries. ------- IV. DISPOSAL ALTERNATIVES Only one of the nine tuna canneries studied •in the development of effluent limitations did, not have a solubles process to reduce stickwater and press liquor into a saleable by-product. This can- nery, located in Puerto Rico, barged the stickwater and press liquor for disposal at sea. Van Camp and Star-Kist dischargethe stickwater and press liquor to the wastewater treatment facilities. These high- strength wastewaters increase the raw-waste load over the values repor- ted in the Development Document, requiring more efficient operation of the treatment facilities than reported in the Development Document to comply with the effluent ‘limitations for total suspended solids and oil! grease. During the NEIC inspection, the feasibility of physi- cally separating stickwater and press liquor from the raw wastewaters was evaluated along with alternative sludge disposal options. SEGREGATION OF WASTEWATER STREAMS Van Camp In the fish meal process, the press liquor and waste streams from the thermal cooker and,desludger are sent to three heated oil- water decantation tanks, operated in series, before being sent to the waste water treatment facilities via the “L-shaped sump [ Figure 4]. The wastewater from the fish meal process can easily be segregated by intercepting the pipe carrying the wastewater to the “L-shaped sump, and routing the wastewater to another location for disposal. ------- 17 The stickwater is discharged to the floor beneath the precookers, f lows by gravity to the collection channel and mixes with wastewaters from the butchering area. These combined wastewater mix with the cooling area wastewaters before discharging to the cooker-juice sump. The wastewaters from the butchering operation flow through a channel on the periphery of the precooker area. The bottom of the channel is approximately 36 cm (14 in) below floor level. The precooker area is about 15 cm (6 in) below the floor level and 20 cm (8 in) above the bottom of the channel [ Figure 5]. The stickwater, when released from the precookers, flows by gravity into the collection channel. The stickwater can be segregated from the other wastewaters by construct- inga concrete wall or barrier on the precooker floor adjacent to the collection channel. A sump could be built inside the wall to collect the stickwater and it could then be pumped to any location in the plant for treatment or disposal. An alternative method of segregation would be to intercept the wastewaters from the butchering and cooling areas and send them to the roto screens instead of the cooker juice sump. This would be more difficult than the first method and could present problems in plant cleanup operations as all floor washings flow into the collec- tion channel: Star- 1 (1St The fish meal plant is located between the large freezer and the warehouse, outside the main processing building. Wastewater from the meal flows by gravity to the rotary screen on the dock [ Figure 3]. Press liquor and other wastewaters from the meal plant could be collected in a sump and pumped to another location. ------- 17 OOR ELEVATION Wastewater Collection Channel / I __ _______ PRECOOKER FLOOR ELEVATION / 72?Y/77 ; Eiev tioq View of C e io FChø neI Wastewater Collection Channel _• \ • _____________ UJ 4 PRECOOKER AREA in I-. • • To Cooler L1J I Juice Sump 0 - I- D — cOOLtNc3 AREA P1 View of Butc erii9, Preco ki an C o15a’g Ar s Figure 5 Schematic of Wosfewqter Collection Channei-Precooker Area Van Camp Seafood Company, American Samoa ‘June-July, 1978 ------- 19 The configuration of the processing •areas is such that waste- waters flow toward the dock. Because most of the wastewaters flow toward the precooker area on the route to the dock, separation of stickwater would be difficult. The precooker area floor is below the plant floor level of the plant. •Stickwater flows.towards the dock, is collected and mixed with other wastewaters from the cooling and packing areas in a gutter before flowing to the rotary screen [ Figure 6]. To physically segregate the stickwater, a concrete barrier would have to be constructed on the precooker floor, leaving a channel or gutter outside the barrier to collect the stickwater so that it could be pumped to another location for disposal or treatment. The other alternative for segregating the stickwater is to inter- cept the other wastewaters before they enter the precooker area and reroute the flow to the rotary screen. The pipe connecting the pre- cooker area with the rotary screen would have to be plugged. This second alternative would require major modifications to the plant’s wastewater collection system. DISPOSAL ALTERNATIVES The Government of American Samoa has informed the canneries that the current method of sludge disposal will be prohibited in the near future and that alternative disposal methods will be necessary. Three options are being evaluated by the canneries; bargingand ocean disposal, dewatering the sludge and using sanitary landfills (if permitted by the GAS), and discharging the sludge to the ocean through the Tafuna sewage treatment plant outfall. If the stickwater and press liquor wastestreams are separated from the other process wastewaters, the canneries will have to stabilize these high strength wastes prior to land disposal.. . The addition of the stickwater and press liquor to the DAF sludge would not only increase odors due to degradation, but the extra volume would require more land for disposal. ------- 20 Dock Collecflon Channel Rotary Screen and Sump NEW THAW AREA I THAW AREA I BUTCHER TABLE Gutter ________________________________________I PRECOOKER AREA Wastewater Drainage from Processing Area Plon View of Dock, B itdiering anti Precooking Areas Figure 6. Schematic of Wasfewater Drainage Precooker Area Star-Kist Samoa, Inc., American Samoa June-July, 1978 ------- 21 Ultimately, something must be done with the DAF sludge, press liquor, and sticlcwater if recovery as a saleable by-product is not feasible or with the residua’ matter after the material is processed. There are only two alternatives !available for the long-term disposal of the wastes or residual matter:- disposal on or in the land, and disposal in the ocean. In the continental United States, land disposal in the form of a sanitary landfill has proved to be the most economical and acceptable method of disposal: Open dumping, which is currently used by the canneries, does not provide controls to prevent contamina- tion of the air or nearby surface and groundwater. Ocean disposal is acceptable if the Environmental Protection Agency determines “that such dumping will not reasonably degrade or endanger human health, welfare, or amenities, or the marine environment, ecological systems, or econmic potentialities” (PL92—532, Sec. 102 (a)). - In Samoa, if recovery is not feasible, there are only two viable disposal methods available for the DAF sludge, and only one method appears to be feasible. Barging to sea will allow for disposal of the sludge, stickwater, and press liquor. Landfilling should only be used for stabilized DAF sludge and only in an emergency. Land disposal should be reserved for solid wastes not amenable to ocean disposal. Ocean Disposal via Barging Barging to sea is the best solution for the Samoa canneries for disposal of sludge, stickwater,.and press liquor. The land is a limited resource while the ocean in this remote sector of the world offers a means to dispose of a non-hazardous and non-toxic waste - which will not unreasonably degrade or endanger human health, welfare, or the marine environment. The disposal site can be selected to incorporate wind direction, current, tides, and ocean floor topography to insure that the wastes disperse adequately. Star-Kist personnel have stated that there are ships and barges available from private ------- 22 individuals who are interested in transporting the wastes for ocean disposal. Additional benefits include reduced operating costs of the wastewater treatment facilities by eliminating the high strength wastewaters and a reduction in the amount of. sludge generated in the DAF treatment system. The pollutant load discharged to Pago Pago harbor would also be reduced. However, the disposal cost for sludge will probably increase, over the.current land disposal method. An Ocean Dumping permit may be issued by the EPA after the cannery (or canneries) application has been reviewed and after a public hearing. The appiication’must contain data supporting the following: 1. Need for the proposed dumping. 2. The effect of dumping on human health and welfare, including economic, esthetic, and recreational values. 3. The effect of dumping on fisheries resources, plankton, fish, shellfish, wildlife, shore lines and beaches. 4. The effect of dumping on marine ecosystem, particularly with respect to: a. the transfer, concentration, and dispersion of such material and its byproducts through biological, physical, and chemical processes, b. potential changes in marine ecosystem diversity, produc- tivity, and stability, c. species and community population dynamics. 5. The persistence and permanence of the effects of the dumping. 6. The effect of dumping particular volume and concentrations of such materials. 7. Appropriate locations and methods of disposal or recycling, including land-based alternatives and’ the probable impact of requiring use of such alternative locations or methods upon considerations affecting the public interest. ------- 23 8. The effect on alternate uses of oceans, such as scientific study, fishing, arid other living resource exploitation, and non-living resource exploitation. In discussions with Star-Kist and Van Camp personnel and with representatives of GAS and Environmental Quality Commission, the best disposal site appears to be outside of the barrier reef, adjacent to the area where the Tafuna wastewater treatment plant outfall terminates [ Figure 7]. At this location the prevailing winds are offshore, the site is about 183 m (600 ft) deep approximately 800 m (1/2 mi) offshore, the currents and tides will not transport the wastes back to shore as the water column is generally transported southwest, parallel to the coast and following the topography of the shoreline. Surface currents are away from the shoreline.* A major problem associated with ocean disposal is the rough seas which occur during inclement weather. Land area for sludge storage tanks is negligible at each cannery. Temporary storage may have to be located off the canneries’ premises. The DAF tanks currently used to hold the sludge prior to being hauled to the disposal pits only have one to two days storage capacity. If temporary storage is not feasible, a backup disposal site on land will be necessary. Land Disposal If ocean disposal is not feasible; and if the sludge cannot be recovered as a food supplement or fertilizer, landfilling is the only alternative. The method requires rigorous waste management because of the following factors: * “Water Circulation Studies of Proposed Ocean Outfalls Tutuila Islands, American Samoa”. Prepared for Government of American Samoa Department of Public Works, CH 2 M Hill, February 1976. ------- / / / / / / / / I , I , (0 / 1 I / / / / / / / / / / — .— — ITAFUNA WASTEWATER DISPOSAL SITE FACILITIES PLAN AND ENVIRONMENTAL ASSESSMENT GOVERNMENT OF AMERICAN SAMOA. DEPARTMENT OF PUBLIC WORKS WASTEWATER FOR AMERICAN SAMOA N-3 0 925’ 1850’ OJ CH2M HILL P8564.0 ‘I .. 24 I - / / , EXISTING OUTFALL I — —--- —-- / / / ( ) / -I — -. - , , , / / / / Figure 7 Ocean Disposal Location Tuna DAF Sludge and Stickwater ------- 25 1. Limited land area 2. Encroachment of residential development as semi-remote areas become accessible 3. Limiting access to disposal area 4. Vector control 5. Odor control 6. Groundwater contamination 7. Need for heavy equipment at landfill 8. Transport through densely populated areas 9. Large sludge volume involved 10. Gas production in landfill The canneries can eitheruse the current leased sites for sludge disposal, can operate a disposal area as a joint venture, or use the municipal sanitary landfill facilities. The use of open pits will be banned in the near future under the provision of the PL94 - 580 the Resource Conservation and Recovery Act. The existing disposal pits will have to be closed and possibly recovered as the need for land for residential and recreational purposes increases. There are very few acceptable disposal sites on the island. The sludge must be dewatered to conserve area. Star—Kist has studied dewatering filters and centrifuges on sludge at their Terminal Island, California facility and have tentatively concluded that the sludge can be effectively dewatered. The dewatering system can be adapted for the Samoa cannery. Because of the concerns of GAS officials and the fact that the contamination of the island’s limited potable groundwater supply could occur, Van Camp should be required to locate another disposal area and reclaim the current site before contamination occurs from the sludge already deposited. ------- 26 The best land disposal alternative would be the joint operation and proper management of a site by the canneries. A suitable land disposal site on the north or east side of the island is preferable to eliminate transport through Pago Pago. The access to the site should be controlled. The dewatered, deodorized sludge would require daily backfilling to control odors and vectors. This would require that heavy equipment be located on site. Operating costs could be minimized through joint operation of the site. A second alternative site is the municipal landfill near Tafuna. The existing heavy equipment already on site could be used to backcover. Two conditions must be evaluated before this alternative is used. The first is remaining land area and projected active life, and the second the volume and continuous supply of commercial and household refuse. If there is insufficient land available, the site cannot be used. If land is available, the sludge could be mixed with the refuse or buried separately. In southern California, sludges are mixed with rubbish on a 2 to 1 ratio, compacted, and backcovered. A cavity or depression is created in the refuse with a bulldozer; the sludge is deposited in the depression and then mixed with the refuse as the bulldozer pushes the refuse into the depression. This method of dis- posal would also provide an acceptable alternative whenever weather prevented ocean disposal. Tafuna Wastewater Treatment Plant Outfall Stickwater, press liquor, and OAF sludge can be discharged from the transport trucks directly.to the Tafuna primary wastewater treat- ment plant’s ocean outfall. The outfall terminates about 106 m (350 ft) from the shore at a depth of 20 m (65 ft). Representatives from both canneries stated that this was the best method of disposal from their viewpoint and could be implemented immediately. While this alternative is economically attractive, especially in the remote area ------- 27 of the South Pacific, the discharge of sludge and untreated waste material from an ocean outfall is prohibited by Federal regulations. Treatment in the GAS Primary Wastewater Treatment Plants The possibility of sending the process wastewater or a portion of the wastewater to the GAS primary wastewater treatment plants was raised by cannery and GAS personnel. Treatment of process wastewater or OAF sludge at the Utulei or Tafuria facilities is not recommended. The Tafuna plant is inactive and raw wastewaters bypass the clarifier and flow to the ocean outfall. •The Utulei plant consists •of sediment and digestion in a clarigester (a two story, separate sludge—digestion tank with a clarifier mechanism in the upper compartment and a digester mechanism in the ldwer compartment — the installation of the second clarigester was never completed), followed by chlorination prior to discharge. The sludge from the clarigester is hauled to the Tafuna plant for disposal. The cannery wastewaters could not be treated effectively at either facility. Technology for tuna wastewaters has prayed that dissolved air flotation is the most efficient treatment method. Chemical addition is required to remove the pollutants. Gravity sedimentation would not produce an acceptable effluent and with the increased detention times in the clarifiers, strong odors could be produced due to rapid microbial action. Placing the stickwater, press liquor, and DAF sludge in the head- works of either treatment plant is not recommended. The primary treat- ment systems are designed to remove solids (and biochemical oxygen demand associated with the solids) through sedimentation. Introducing the OAF sludge into the headworks does not comply with best engineering principles which dictate that once a pollutant is removed, it is not returned to the wastewater unless it is an integral part of the process. The sludge would be partially removed in the clarifier and the remaining fraction would be discharged. It is probable that the effluent would not comply with the NPDES permit limitations for solids. ------- 28 Stickwater and press liquor would receive marginal treatment if these two high-strength wastewaters were discharged to the primary treatment plants. Some solids removal would occur, but the emulsified O/G would not be removed and could cause operating and maintenance problems. Additional treatment would be required to reduce the efflu- ent pollutant load to acceptable levels. The majo.r benefit for discharging process wastewater to the GAS treatment plants is to remove the waste sources from the inner harbor area. Only process wastewater treated in the OAF system should be discharged to the GAS treatment plants; secondary treatment would be required to significantly reduce pollutants. The tuna cannery process wastewaters at Terminal Island, California are discharged after DAF treatment to the municipal secondary treatment plant. RESTORATION OF EXISTING DISPOSAL SITES The location currently used for sludge disposal by both canner- ies are situated in areas where significant environmental damange could occur. An earthen side of one of the pits at the Star-Kist site on top of Matauloa Ridge failed in January, 1979 and sludge entered Larsen Bay. Additional failures or overflows can be expected -if the sludge disposal occurs. The Van Camp disposal site is poten- tially more damaging because it overlies the fresh water drinking source. Since liners were not installed in the pits, the leachate can percolate through the porous soils to the water table. Once con- tarnination occurs, treatment and decontamination will be expensive. ------- 29 Both -sites should be closed and the area restored. Two methods of restoration are feasible if ocean disposal of the DAF sludge is implemented. The sludge should be pumped back into the-transport trucks from the pits, hauled to the canneries and placed in a barge for ocean disposal. The empty pits should then be backcovered and returned to their natural contours. A second method would be to remove a portion of the sludge for ocean disposal, then mix earth in with soil and compact the mixture with heavy equipment. This second method has a major -disadvantage in that the mixture may have to be removed at a later date if building occurs on the sites. Once the disposal sites are restored, the area should be sprayed with an industrial deodorant to destroy residual odors. Proper res- toration should prevent odors from being emitted. If ocean disposal of DAF sludge is not implemented, then the sites should still be reclaimed and restored as stated above. The recovered sludge should be placed in the new disposal area selected by the canneries and approved by the Government of American Samoa. ------- V. ODOR SOURCES AND CONTROL AT THE TUNA CANNERIES ODOR SOURCES In the processing of tuna and fish meal, strong and obnoxious odors are emitted in the forms of H 2 S, NH 3 , mercaptans, and amines. These odors are detectable next to the canneries and across the Pago Pago harbor under certain wind conditions. Citizen complaints have been made to the Governor’s office. Because odors are emitted from various processes and locations in the canneries and have a masking effect, all of the sources cannot be identified. However, the major sources of odor include the precooker area when the cookers are opened and drained, the steam driers in the fishmeal processes, and the surge tank and DAF wastewater treatment units. Control of odor emissions from these sources would significant- ly reduce the overall odor problems. ODOR CONTROL When the tuna plants were originally built, control technology did not exist. Therefore, retrofitting the canneries to control odor with existing equipment will be expensive. However, technology is available which can partially control odors emitted from the precookers and control most of the odors from the fish meal process. Odor control at the wastewater treatment facility is limited to masking agents or chemical oxidation. ------- 31 The canneries can exhaust the inside air through fans to the atmosphere. The exhaust vents could be connected to a collection system and passed through a scrubbing system. The technology exists to remove SO 2 , NH 3 , NH 3 , soluble mercaptains, and aniines, using limed sea water as the scrubbing media. Control of the insoluble inercaptans and less odorous compounds is accomplished by reacting the air stream after scrubbing with chlorine gas, sparged into a reaction section. The air stream could then be incinerated to remove refractory odors. - Van Camp personnel stated that a packed-bed, cross-flow water scrubber will be installed to control the exhaust air from the fish meal driers. This technology is available to Star-Kist. Additional odor control in the fish meal process can be accomplished by processing fish scrap as soon as possible. This scrap should not be accummulated for processing several days later, but should be processed on a daily basis. ------- APPENDIX ATTENDANCE AT CONFERENCE ON SLUDGE DISPOSAL ------- 33 NAME APPENDIX A ATTENDANCE AT THE CONFERENCE ON SLUDGE DISPOSAL PROBLEMS June 22, 1978 AFFI LIATION Barrett Benson (Chairman) Dr. Nofo Siliga Randy Morris Abe Malae Pati Faiai Bill Perez Orley Bennett Ken Miller Steve Spangler Ed Stockwell John Broughton Jack Holland Jack Kuijis National Enforcement Investigations Center, EPA Director of Public Health, GAS General Manager of Solid Waste, GAS Manager for Water Utilities, GAS Special Assistant to the GOvernor, GAS General Manager, Van Camp Samoa Plant Engineer, Van Camp Samoa Quality Control Manager, Van Camp Samoa Environmental and Energy Conservation Engineer, Van Camp San Diego General Manager, Star-Kist Samoa Environmental Engineer, Star-Kist Samoa Plant Engineer, Star-Kist Samoa Quality Control Manager, Star-Kist Samoa ------- |