Alternative Sanitation Technologies

AlternativeSanitation

Technologies 5INTRODUCTIONThis chapter discusses a number of new and innovative ap-proaches to providing adequate sanitation systems to NativeAlaskan communities. Many approaches have been proposed, butfew have been evaluated and tested under realistic conditions.There is, however, a growing need to improve sanitation systemsat a realistic cost and with confidence in safe and practical results.For more than three decades, Federal and State efforts to improvewaste sanitation among rural Native communities in Alaska havefocused on building centralized conventional piped systems.However, these systems have a high initial cost, especially whenbuilt in remote regions with harsh cold climates, and because ofthe environmental extremes, operational maintenance is also dif-ficult and costly. To date, only 72 of the 191 rural Native commu-nities identified by the Indian Health Service have been providedwith piped sewerage services. The level of sophistication of wastedisposal technologies operating in remote Alaska varies signifi-cantly among villages, ranging from complex piped sewerageservice with flush toilets to the rudimentary privy and honeybucket systems. Between these two extremes, one finds technolo-gies such as the septic tank and the truck haul approach.

For the most part, the sanitation technologies operating in ruralAlaska are merely modifications of approaches designed decadesago for use in more moderate climates. Recently, a modificationof the conventional truck haul system tested in the City of Meku-ryuk (Nunivak Island, Yukon-Kuskokwim region) is being re-garded as a promising alternative to honey buckets. Other sys-tems, such as composting, incinerating, or propane toilets havealso been proposed. These alternatives may overcome some ofthe cold-temperature problems encountered by larger conven-

e------#——————————— IIt+~— ‘ - . . .

72 I An Alaskan Challenge: Native Village Sanitation

tional systems and be more effective than honeybuckets indisposing of waste and reducing humanexposure. The fact that these systems can incorpo-rate low-flush or waterless toilets and eliminatethe need for maintaining sewage lagoons is alsoadvantageous. However, because these systemsdo not require potable water, they defeat, in theview of many, the objective of promoting an am-ple supply of potable water and thus better sanita-tion practices in the villages.

Although potentially useful, some of the otherinnovative technologies discussed in this chapter,such as the National Aeronautic and SpaceAssociation (NASA) waste treatment methods,thus far appear either too complex and too expen-sive for immediate application or are just in theirpreliminary phase of development. (Currentcooperative efforts among Federal and State gov-ernments and private organizations to demon-strate NASA’s technologies, however, appear tobe potentially useful for transferring knowledgeand technical experience to remote communitieswith waste sanitation problems.) Others systems,though already developed, suffer from limited in-formation about their actual full-time perfor-mance in treating human waste in areas of harshclimate such as rural Alaska. Finally, an overallmechanism to test and evaluate new systems un-der actual conditions in these Alaskan villages hasyet to be developed. Until this is done, it will bedifficult to select a system that is the most cost-ef-fective, safe, and acceptable to the communitythat must operate it.

DESCRIPTION OF NEW ADVANCEDSYSTEMS CURRENTLY PROPOSED FORALASKAN VILLAGES| Cowater Small-Vehicle Haul SystemThe Cowater small-vehicle haul system, a varia-tion of the larger conventional truck haul systemand developed by Cowater International of On-tario, Canada, is currently being evaluated in theCity of Mekuryuk (Nunivak Island, Yukon-Kus-kokwim region) as a possible sanitation approachfor Alaska (figure 5-1 ). This technology involvesthe use of all-terrain vehicles (ATVS; during the

SOURCE Cowater International Inc , Ontario, Canada, Mekoryuk Sew-

age Haul System Development Prototype Household DemonstrationFinal Report, October 1993

summer) and snowmobiles (for winter opera-tions) equipped with a tow trailer and a small vac-uum/pressure tank to remove wastewater fromhouse holding tanks (figure 5-2).

Although similar in concept to the truck haulapproach, the Cowater system does not require ex-pensive conventional vacuum trucks and is lesscostly to maintain and operate. In addition, it doesnot require load-bearing roads and snow removalequipment for its operation. The major elementsof this system are: a dual flush toilet, an in-housewater storage tank, an outside wastewater holdingtank, and a small haul vehicle equipped with ahaul tank.

Dual Flush ToiletThe dual flush toilet looks like a conventionalhousehold toilet, can be connected to a gravity-fed

Chapter 5: Alternative Sanitation Technologies | 73

SOURCE Cowater International Inc Ontario, Canada, Mekoryuk Sew-age Haul System Development Prototype Household DemonstrationFlnal Report, October 1993

water source, and does not require a pressurizedwater supply. It is designed to control the amountof water consumed, requiring only 1 pint perflush. Sometime in early 1995, one firm expectsto begin the large-scale manufacturing of the dualflush toilet ( 186,1 87,237).

In-House Water Supply SystemThe in-house system consists of a tank capable ofholding up to 150 gallons of potable water. De-pending on the desired level of operation, the in-house water supply system can provide water fortoilet flushing only; can incorporate a washbasinoption in which the water used for hand washingcan be recycled as flush water; or can supply waterfor washing, cooking, and drinking. A small elec-tric pump fitted on the tank provides a constantsupply of water whenever needed.

The water stored in the water supply tank is de-livered from a small tank mounted on a wagon anddrawn by a small haul vehicle. The operator usesthe air compressor at the local water treatmentplant to draw water from the large storage tanks of

fill the small air tank located on the wagon withcompressed air. The compressed air is used toforce the water from the haul tank into the watersupply tank located inside the house.

Wastewater Storage TanksDepending on the house’s design and the user’sneeds, the sanitation system may be equippedwith either an indoor or an outdoor wastewaterholding tank for discharging and storing wastes.Made of a flexible rubber or plastic bladder andaligned by a rigid enclosure, indoor holding tankscan store up to 100 gallons of wastewater. Indoortanks are evacuated by a blower that pressurizesthe tank, pushing the sewage through a pipe intoa haul vehicle outside.

Outdoor holding tanks, on the other hand, areheavily insulated and capable of holding largervolumes. These tanks are generally set on skidsalongside the house and are connected to the in-door sanitation system by insulated pipes. Out-door tanks are emptied the same way as indoortanks. Outdoor holding tanks are preferred to in-door ones because they remove the sewage fromthe home and eliminate the need to build steps toreach the toilet (120).

Haul Tank and Haul VehicleA tank designed for hauling human sewage fromthe house to the disposal area is made of stainlesssteel and sized to exceed the capacity of holdingtanks.

As shown in figure 5-2, the haul tank can bemounted on a trailer fitted with wheels or skis andhauled by snowmobile, ATV, or a small tractor.With the exception of the pump-evacuated systemin which a pump is provided, the system operatoris required to use the blower located on the haulvehicle to empty the collected waste into the haultank. Once the tank is filled, the operator pulls it tothe sewage lagoon or disposal area and empties itby gravity. The pump-evacuated system allowsthe operator to empty the indoor holding tank intothe haul vehicle by turning the pump-out switch

the water treatment plant into the haul tank and to located on the side of the house.


According to Cowater reports, the field demon-stration at Mekuryuk has provided an opportunityfor increasing the understanding of the system’sengineering and performance, and for successful-ly working with Native residents in achieving thecommunity’s desired level of sanitation and aes-thetics (82,1 19,120,1 85).

| The “AlasCan” Organic Waste andWastewater Treatmentl

The AlasCan is a modular, high-technology, self-contained comporting system designed to handlesanitary and kitchen wastes and greywater(181 ).2

The essential components of the AlasCan systemare a custom-made comporting tank and a ce-ramic toilet (consisting of either the fully auto-matic, computer-operated Nepon Pearl foam-flush toilet 3 or the pedal-operated vacuum toiletknown as SeaLand VacuFlush). This combina-tion, according to its designers, provides the userthe comfort of a flush toilet and the advantage ofcomporting treatment (97). The AlasCan is alsoequipped with a kitchen waste disposal systemand a greywater treatment tank.4 To avoid prob-lems experienced with other models in the past(e.g., odor escaping into homes), AlasCan design-ers built the toilet and compost treatment tank astwo separate units (146).

The AlasCan comporting technology has beenin use in several facilities in Alaska, Canada, andthe lower 48 States. Most of the Alaskan sites,however, are National Guard armories. One par-ticular unit is being used on an oil drilling rig nearPrudhoe Bay. Field tests are also being conductedat a few selected locations in the Yukon-Kuskok-

wim region to evaluate its potential for use inAlaskan Native villages.

Major Components of AlasCanCompost Technology

Comporting TankThe central component of the AlasCan comport-ing system is a double-walled “superinsulated”plastic tank containing a fully automated chamberwith aerobic bacteria and red worms to decom-pose sanitary waste or backwater into a safe, fer-tile humus material similar to garden soil(6,7, 182).5 Wood shavings are added to reduce ex-cess liquid in the tank and to provide the carbonand other minerals needed for effective biodegra-dation.

The treatment tank is equipped with a series ofbaffles, air channels, and mixers. A fan is alsoused to draw warm air into the treatment tank topromote organic decomposition of the waste (fig-ure 5-3). To improve the rate of decomposition,the treatment tank is fitted with two items: auto-matic churners or agitators capable of mixing thewood shavings, red worms, and waste; and sprin-klers, which reincorporate accumulated liquidsinto the mixture when needed (6,7, 181 ). The com-puter-controlled agitators are set to operate forabout 20 minutes daily so that recently disposedwaste is properly mixed, and the compost pile lev-eled (6,7). Installation of an auxiliary heating unitmay be required in locations where ambientconditions could force the internal temperature ofthe comporting tank to drop below 60 “F.

The treatment of human waste with the Alas-Can comporting technology results in three by-

1 This technology is commercially known as the AlasCan Model 10 system.2 Greywater is household wastewater without toilet waste. It consists primarily of discharged water from bathtubs, showers, sinks, and ap-

pliances such as washing machines and dishwashers.3 Developed by the Japanese firm Nepon, Inc.

4 tie ~)ptlona] feature offered by the manufac~rer of this system is a wall-mounted urinal equipped with the same foam-flush action as the

toilet system.

5 me Iem backwater refem t{) the urine, fecal matter, and related debris such as toilet paper deposited in a toilet, as well as the water used to

transport these materials

Chapter 5: Alternative Sanitation Technologies I 75

Organic Solid Waste Treatment System

2“ garbage disposal input

separates userfrom compat mass

Organic Wastewater Treatment System

Low-pressure air-powered

Surface skimmer water transport systemSludge removalsystem (to hand-

/ operated removalpump)

Effluent (outlet)pipe toabsorption field\

Clanficat]on baffle /

Y x Influent (Input)pipe

\Large surge chambercapable of handling

/

\

\ \

washing machmes,Polyurea plastlc shells dishwashers, bathtubs,separated by 4“ rigid

Clarification Aerobic reactionsinks, etc.

polyurethane insulation(greater than R20) chamber chamber

Low pressureaerator

SOURCE Al Gelst, Markellng Director AlasCan Inc Fairbanks Alaska, personal communlcatlon, Nov 23, 1993


products: water vapor and carbon dioxide, whichare released through an insulated vent installed inthe home or building, and humus, which collectsin a tray in the lower portion of the tank. The aero-bic nature of this technology prevents the genera-tion of malodorous methane gas (181).

Its modular design makes the AlasCan systemeasy to install and maintain. For homes built onslab floors or with limited crawl space, AlasCanuses a special vacuum flush toilet6 to lift waste upto the comporting tank. Lifting of greywater intothe treatment tank is accomplished by a transfervacuum pump fitted to a small reservoir (6,7,145).For homes without running water, the bathroomtoilet is fitted with a small reservoir or water tank.

Ceramic ToiletThe AlasCan system is an improved design overthe internationally known Clivus Multrum com-porting toilet. 7 Such improvements include,among others, automation of the comportingprocess; connection of the comporting tank to amodern foam-flush toilet; and addition of a sepa-rate greywater treatment tank unit (181). Toiletsmay be of a “straight drop” waterless or a foam-flush design. The foam-flush toilet design uses asmall air pump, which upon flushing, mixes asoaplike substance stored in the tank with water toproduce a soapy foam layer inside the bowl thatcarries the waste down to the treatment tank withminimal splashing. The use of a biodegradablesoap is also advantageous because it minimizesthe need for toilet cleaning. When the toilet isflushed, waste is discharged to the insulated treat-ment tank where it is decomposed by organisms(bacteria and red worms) into organic humus(181).

Kitchen Waste Disposal SystemThe AlasCan system can also be equipped with asmall garbage disposal sink fitted with a sprayer.

6 Known as the Seaiand VacuFlush toilet system

This device is typically located in the vicinity ofthe kitchen sink. Garbage, placed in the disposalsink for processing, is subsequently piped to thetreatment tank where human waste is also treated(181).

Greywater Treatment TankIn addition to treating black water, the AlasCancomporting technology can be used to treat grey -water (figure 5-3). The treatment of greywater isconducted in a three-chambered tank fitted with aseries of baffles and filters. After treatment, thetreated water is filtered and released into theground, while the remaining solids are sent to thecomporting tank for further decomposition. Ac-cording to the manufacturer, treated wastewatercan be returned safely to the environment becausethe AlasCan system removes the majority of pol-lutants found in it, including nitrites, volatile or-ganic compounds, suspended solids, and organicmatter (6,7,170).

1 Phoenix Comporting ToiletThe Phoenix comporting technology has been de-signed primarily for indoor installation. Its com-pact shape results in small tank and maintenanceareas. The major components of this technologyare a toilet, a kitchen waste inlet (optional), and acomporting tank (figure 5-4). Electricity can besupplied by an independent energy source, such asa photovoltaic system or by the small plug-in al-ternating current (ac) power plug supplied withthe unit.

Use of the Phoenix comporting technology inrural communities of Alaska is limited in compar-ison to areas in the continental United States andCanada. The School of Environmental Engineer-ing of the University of Alaska Anchorage willsoon field-test two Phoenix units as part of an on-going effort to identify potential alternatives tohoney buckets in Native communities (196).

7 The Clivus Multrum system was first developed in Sweden more than 60 years ago with the primary purposes of recycling waste and

conserving water and land.


Toilet II

Exhaust1

SOURCE Advanced Compostlng Systems, Whlteflsh, MT “Testing the Phoenix Compostlng Toilet,” Mar 24, 1991 Advanced Compostlng Systems,Whlteflsh MT Evaporation System, ” Apn 1992

Major Components of Phoenix turer, certain models allow the connection of up toToilet System three toilets (3,197 ).8

Toilet System Kitchen Waste Disposal InletThe toilet provided in the Phoenix comporting Manufacturers of the Phoenix comporting systemsystem is contemporary in design and made of have built two types of kitchen waste disposal op-white plastic. The bowl is attached to the com- tions. One model consists of a stainless steel rimposting tank by a chute and secured with a special- and bowl fitted with a maple chopping block cov-1 y designed connector. According to the manufac - er for installation in kitchens with counter tops.

xl f ,n~tal latlon ~)fa ~rlna] is ~e~lre~, [he hon~eowner” needs only to mount it on the toilet room wall and connect II to the C(JnPS@ tank with

a vinj I h(}sc. Urinals manufactured for the Phoenix system are generally made of steel m p~rcelain and are trapless in their design (3).

78 I

The

An Alaskan Challenge: Native Village Sanitation

other is an aluminum access port that can beinstalled either on countertops or on vertical sur-faces (3).

Comporting TankThe Phoenix operates much like a garden compostpile, requiring adequate food, air, moisture, andtemperature to support the breakdown of sanitaryand kitchen wastes into a stable humus-like mate-rial. Depending on the model, a Phoenix treatmenttank is capable of safely comporting the sanitaryand kitchen wastes of four full-time users (ModelR200) or eight part-time users (R201 ). OtherPhoenix models, such as the R199, have smallertreatment capacity because they are generally in-tended for cabin use (two people full-time; moreif use is intermittent).

The Phoenix comporting system is ventilatedby a multiple speed, 12-volt direct current (de),4-watt fan.9 The continuous insulation of thewalls of the treatment tank seals the ventilationpath and allows the air baffles to perform as heatexchangers; this, in turn, promotes heat retention(up to 80 percent) and increased decompositionrates. Aerobic conditions are maintained by airbaffles installed on the side walls of the tank toaerate the compost pile and by rotating tines tokeep the compost materials from compacting. Useof coarse wood shavings is required as a bulkingagent (2,4,5,196,197) .

Transport of composted material through thetank is facilitated, according to the manufacturer,by the vertical and uncomplicated tank design,and by the incorporation of rotating tines. A built-in hand pump allows accumulated liquids to besprayed back on the compost pile to maintainproper moisture. The sloped design of the internaltank floor helps separate treated liquids fromtreated solid byproducts. A liquid evaporatorequipped with a small storage tank for peak load-ing is also used to reduce the amount of treated liq-uid byproduct that must be drained from the Phoe-nix system to a holding tank or to the outside

environment (small leach field, soil bed, etc.)(197). For conditions in which liquid effluentscannot be discharged, the comporting tank isfitted with a highly specialized system (consistingof a 50- to 100-gallon storage tank, an evaporationtower, a pump, a dc fan or ac blower, and controlsand sensors) capable of evaporating between 5and 13 gallons of liquid effluent per day (2,5).

To ensure proper system operation in areascharacterized by subfreezing temperatures, how-ever, it is critical that the Phoenix tank be locatedin a well-heated area and that all vent pipes be in-sulated to reduce condensation and freezing(1 11,1 12,197).

Maintenance RequirementsThe Phoenix treatment tank (approximately 3 feetwide, 5 feet long, and 8 feet high) requires about5 feet of additional space in front of the tank, andabout 1 foot of clearance above the tank, for prop-er operation and maintenance. The degree ofmaintenance required by this technology dependshugely on the frequency of use. The manufacturerrecommends that bulking agent be added—about1 gallon for every 100 uses—and thoroughlymixed into the waste pile. A heavily used systemrequires more frequent attention and care.

Similarly, the amount and frequency withinwhich by-product materials must be removed de-pend on the extent of use, the rate of decomposi-tion, and the maintenance of the unit. Accordingto the manufacturer, treated materials should beremoved at least once a year, starting after the firstyear the system has been in operation. It is esti-mated that about 8 gallons of humus would haveto be removed from the tank for every 1,000 uses.

| Sun-Mar Comporting ToiletsSun-Mar Corp. of Ontario, Canada, has developeda series of composting toilets capable of biologi-cally treating human and kitchen wastes, toilet pa-per, and otherplication of

organic materials (figurethe Sun-Mar system

5-5). Ap-in rural

9 A 24-vtdt dc fan is also available.


1 .Seat2. Bowl liner

(removable)3. Toilet top4. Main shell5. Drum bearing6. Step support7. Compost drawer8. Drum door hinges9. Drum door

10. Crank shaft11. Drum locker12. Crank handle

13. Drum drain screen14. Fan mounting plate15. Fan 30 Watts with

speed control16. Crank sprocket17. Drum sprocket

(moulded into drum)18. Drum19. Insulation base20. Heating element 250 Watts21. Insulation22. Vent hole

SOURCE Sun-Mar Corp , Burlington, Canada, “Sun-Mar Cottage Toilets, ” undated

communities of Alaska has been limited in thepast. The School of Environmental Engineeringof the University of Alaska Anchorage plans toconduct a field test of this technology in an effortto evaluate its feasibility as an alternative to honeybuckets (197).

System CharacteristicsSun-Mar comporting toilets are available in elec-tric (ac, dc, solar) and nonelectric designs. During

operation, waste is transformed into humus byheat from the compost pile or a heating element,oxygen provided by the ventilation system, andorganic material (e.g., peat moss) added to the sys-tem by the homeowner (236).

The fiberglass and high-grade stainless steelconstruction, according to the manufacturer, pro-tects Sun-Mar compost toilets from structuraldamage at freezing temperature. As with mostcomporting systems, however, temperatures be-


low 60 ‘F will adversely affect the rate at whichthe Sun-Mar system can degrade waste. For thisreason, the manufacturer recommends that the 1l/2-inch vent pipe provided with the system be in-sulated adequately.

The use of a 30-watt centrifugal blower fan toprovide a negative pressure within the treatmentunit prevents back-draft and, with it, the formationand release of offensive odors from the toilet sys-tem into the home environment. Rotation of thecomporting medium with the mixing system,along with the addition of peat moss, helpsachieve rapid, odorless treatment of the waste(77,169,236).

The Sun-Mar models considered most likely tobe used in rural Alaska are:

Compact and X-L (EXCEL)The “Compact” model is a self-contained com-post toilet system designed to accommodate low-capacity use (1 to2 people for residential use). TheX-L model is recommended for larger demand (2to 4 people). Both models are available in electricand nonelectric versions.

In addition to the toilet, these units containthree separate chambers for waste comporting,compost finishing, and the evaporation of liquideffluents. Comporting is carried out in a unit orchamber called Bio-Drum in which wastes aretumbled to achieve better mixing, aeration, andhigher rate of comporting. Liquids are evaporatedby means of a 250-watt electric heating unit with areplaceable thermostat installed at the base, andare drawn out of the system through a vent by asmall 30-watt fan. The overall weight of theseunits is about 45 pounds, and their dimensions are22 1/2 inches wide; 31 inches high, and 32 incheslong (194,236).

Centrex and Water Closet Multrum ModelsSun-Mar Corp. has also developed a comportingtoilet system consisting of a specially designedlow-flush, ceramic toilet10 connected by a 3-inch

pipe to a comporting unit located some distanceunderneath the floor on which the toilet has beeninstalled. Weighing nearly 60 pounds, the com-porting unit of these models is about 33 incheswide, 25 inches deep, and 26 l/2-inches high.These toilets can accommodate the demand of 3 to5 full-time users and twice as many under part-time use conditions.

Although the toilet does not have a holdingtank, the use of water to flush waste into the com-porting unit (less than 1 pint of water per flush) re-quires that the house be connected to a piped watersystem. Although a septic field is not required,these comporting systems have been fitted with adrain pipe for situations in which complete evapo-ration of the liquid cannot be accomplished.

Maintenance RequirementsTo maintain the Sun-Mar compost technology ingood condition, the homeowner must add one cupof peat moss per person per day plus, if available,organic materials or waste such as vegetable cut-tings and greens. Adding warm water is also rec-ommended whenever the compost appears to betoo dry. The compost must be mixed and aeratedevery third day; this is easily done by turning thecrank handle on the side of the toilet. Removal ofthe solid byproduct of comporting (humus) is rec-ommended at least once a year for Sun-Mar sys-tems undergoing residential application; less fre-quent use requires less maintenance (236).

| Incinolet Electric Toilet SystemINCINOLET toilets have been designed for a va-riety of applications, including, homes, cabins,barns, shops, boat docks, houseboats, barges, mo-bile homes, remote work areas, and laboratories.Most systems are about 15 inches wide, 20 incheshigh, and 24 inches deep (figure 5-6). Dependingon the model, INCINOLET toilets can accommo-date up to 10 persons (183,184,199,211).

The INCINOLET toilet is designed to use elec-tric heat to reduce human waste—including urine,

10 Manufactured by SeaLand Technology, hIC., of Big %Irlet ohi~).

Chapter5: Alternative Sani@tion Techooiogies \ 81

~“——~”—

SOURCE Research ProduWBankenshlp Dallas T~ ‘Incinolet ‘hatE\ectl\~ TOIlel “ an installation and maintenance manual 1993

Solids, and toilet paper—--to a small amount of ash,which can then be discarded periodically as trash.Installation of INICINOLET systems involves twosteps: installing a pipe through the bathroom wallto vent incineration gases to the outside, and plug-ging the electric cord supplied with the unit into anearby outlet (21 1).

Placement of a bowl covering or insert made ofpolyethylene film prior to each use prevents hu-man waste from contacting the bowl surface andreduces the risks of exposure to users. The pur-

pose of the plastic insert is to capture the incomingwaste or urine. Once use is completed, the residentcan flush the INCINOLET system by stepping onthe toilet’s foot pedal, which causes the plastic in-sert and its contents to drop into the incineratorchamber located at the bottom of the toilet.

Although incineration of waste begins immedi-ately after it enters the chamber, home residentscan use the toilet even while the incinerator is run-ning, because combustion heat and vapors arevented to the outside to prevent the surface of thebowl from getting hot. INCINOLET can also al-low the accumulation of up to four deposits beforeflushing (i.e., burning).

CombustiOn of waste at 1,400 oF eliminates

bacterial growth, while a platinum-based catalyst,similar to those used in automobile exhaust sys-tems, removes offensive odors from the treatedwaste or ash.

Because electric toilets are appliances, severalfeatures have been incorporated into the INCINO-LET system to ensure its safe operation (1 83,2 11).These include an operating timer that limits theheating cycle to 1 hour; a temperature controller tolimit heater temperature; and a safety thermostatto prevent overheating of the system m case ofblower failure. A second thermostat has also beenincorporated into the design to eliminate the ex-tremely high temperatures that may occur follow-ing failure of the temperature controller. Eventhough it appears promising, there are few perfor-mance data on the use of INCINOLET in rugged,extremely cold environments such as that of ruralAlaska.

Maintenance RequirementsTo ensure proper operation, emptying of the ash isrecommended at least twice a week. wiping sur-

faces with a damp cloth is also suggested for over-all cleanliness” The manufacturer advises inspect-ing the level of the catalyst (white pellets)contained in the incineration chamber every sixmonths (183,21 1).

The Storburn Propane Toilet SystemThe Storburn technology is a compact, self-con-tained toilet designed and manufactured by Stor-bum lntemational, Inc., of Ontario, Canada, to in-cinerate human waste. Models available canoperate with propane or natural gas. Most applica-tions to date are found in cabins, mobile shelterunits, and industrial and construction sites. Ac-


.

.●

●

APPROX.96,!

1 )/ z

Vent Kit No. VKL-1 MO

Propane

J’

Vent Kit No. VKL-1

SOURCE Storburn Int , Inc , Ontano, Canada, “Storburn: Pollution-Free Toilet, ” 1993

cording to the manufacturers, about 100 units arealready in use in Alaska (144,234).

The Storburn system consists of a toilet madeof fiberglass reinforced with plastic material, astainless steel top deck, and a 3-gallon waste com-bustion chamber made of cast nickel alloy (figure5-7). Nearly 4 1/2 feet high and weighing 170pounds, the entire toilet system covers a floor areaof only 18 by 31 inches. A vent and a hookup to apropane or natural gas tank are required for opera-tion.

The Storburn toilet can accommodate between40 and 60 uses before incineration becomes neces-sary. Prior to burning of the waste, a chemicalpowder is added to the toilet system and a specialcover is placed on top of the bowl to trip a safetyswitch, which ignites a pilot light and the burnerthat heats the combustion chamber. The burnershuts off automatically immediately after allwastes are burned. Depending on the ambientconditions of the area in which it is used, the Stor-bum toilet system can bum between 10 and 16


maximum-capacity loads (i.e., 600 to 900 uses)with a full 100 pound propane cylinder. The timetaken to bum a loaded storage chamber is general-ly about 4 1/2 hours (234).

According to its manufacturers, the Storburnsystem is easy to maintain because it has no mov-ing parts and only a few simple electrical controls.The high temperatures reached inside the wastestorage chamber sterilize the chamber walls, thuseliminating the generation of foul odors and theneed for cleaning the chamber. The only mainte-nance required is cleaning the burner about once ayear (234).

| Entech Thermal Oxidation SystemEntech, Inc. of Anchorage, Alaska, developed athermal oxidation process to treat solid waste andsewage from small, remote communities. In addi-tion to incineration treatment of sewage, thistechnology can be used to treat other wastes andprovide some energy as a byproduct.

The Entech thermal treatment system has threebasic parts: a primary combustion cell or refrac-tory chamber, where trash and other communitywastes are loaded without preprocessing or pres-orting and are heated—by gas, diesel, or propanetorches—to convert them into a combustible gasand other incinerated materials (inert ash, glass,metal, etc.). 11 Removal of treated waste materialsfrom the insulated chamber is required every 6 to10 cycles.

12 A secondary combustion chamber

receives and ignites the gas produced by the pri-mary cell to 2,000 “F to eliminate pollutants andproduce a smoke-free, hot air and water vaporemission. According to company literature, “noodor from combustion during the operation of thesystem is detectable” (134,135,209).

The third major component of this technologyis a computerized device called the process logiccontroller, designed to automatically control the

system’s operation and reduce the need for hiringhighly trained operators. This device monitors thetreatment, finishes the cycle, and shuts down thesystem within a period of 10 to 12 hours after op-eration was initiated. About 2 or 3 hours aftershutdown, the primary cell will be sufficientlycool to allow the next load of waste. Another ad-vantage of the process logic controller is that itpermits remote monitoring of performance, andrepair diagnosis of the system, by phone from An-chorage to anywhere in the State of Alaska.

Depending on the community’s waste disposalneeds, schedule of operation, and design prefer-ences, the chambers may vary in size, number, andability to recycle waste heat. According to itsmanufacturers, the Entech system can be adaptedto operate on a daily, every-other-day, or weeklybasis. The configuration of the Entech system canbe further designed to collect the radiant heat pro-duced during operation for use in a number of dif-ferent applications. They may include space heat-ing, water heating, steam production, andrefrigerated warehousing—through the use of re-verse chillers ( 135,209).

According to company officials, the operationand maintenance (O&M) of the Entech ThermalOxidation System are relatively simple. An indi-vidual who has the capability to read and write atthe high-school level, and is familiar with equip-ment and truck maintenance, is generally quali-fied to run and service this waste treatmenttechnology. Entech can train operators and supplytechnical O&M assistance.

Although not specifically designed and built totreat human sewage, the thermal oxidationtechnology (figure 5-8) could potentially be use-ful in some communities because it may solveboth their honey bucket and their solid waste(trash) disposal problems (208). The initial capitaland O&M costs of the Entech technology vary ac -

I I According t. Cf)nlpany officials, the En[cch system can treat, in addition to trash, a number t~f waste streams including nledical waste, [ir~s

(with the rims), w(md, c(ms[ructl(m ddms, fum]turc, oil filters, paint, household cleaning and other chemicals, fish net, absorhent b(wn~s and

pads, ship wastes, honey bucket waste, used oil, tank b(m(m~s, fish cleaning waste, and oily ship waste (bilge water).


SOURCE Michael G. Pope, President, Entech, Inc., Anchorage, AK,personal communication, Apr. 7, 1994

cording to the size of the community for which it isbeing considered. High capital and operationalcosts might make the application of this technolo-gy for treating honey bucket waste difficult incommunities with few economic resources. How-ever, expanding its application to other wastestreams, such as trash, might make it cost-effec-tive overall. The necessary technical and econom-ic studies of the Entech system for treating solidand sanitary wastes in a rural Alaskan village havenot been conducted to date.

| NASA’s Controlled EcologicalLife Support System

The Controlled Ecological Life Support System(CELSS) is one of the cooperative applied re-search programs of NASA that might be useful in

solving future sanitation problems in rural areas ofAlaska. The major objective of CELSS is to testadvanced technologies to support human life inharsh environments such as the moon, Mars, andremote or isolated regions of Earth (96,192). Theprogram focuses on technologies that, 1) produceand recycle food, air, and water in a way that re-sembles natural processes; and 2) eliminate theneed for frequent resupply, and overcome theharsh environmental conditions.

13 Another por-

tion focuses on developing technologies capableof treating human waste and recycling wastewaterin a manner that reduces health and environmentalrisks of exposure. NASA plans to demonstratetechnologies relevant to sewage treatment in twoprograms: the Antarctic Analog Project and theLife Support Research Testbed in Barrow,Alaska. The possibility for commercialization ofthe technologies employed in these programs willalso be explored. It is too early to evaluate whetherthese systems could be adapted to solve sanitaryproblems in Native Alaskan villages.

Currently, several advanced waste processingtechnologies are being tested by Ames ResearchCenter scientists at Moffett Field, California, forpossible application in rural Alaska, Antarctica,and space flight (95,96,308,309). Examples of po-tential candidates include the following: 14

Incineration—This approach would involvethe thermal treatment of concentrated humanwaste to produce dry, inorganic ash and gases(e.g., water vapor, carbon dioxide). NASAplans testing to evaluate overall system perfor-mance, energy consumption requirements, andlevel of treatment that may be needed after in-cineration.

I J Based on past Pilot demonstrations of minifarrns and fish ponds conducted at the Ames Research Center, NASA personnel have designed

and tested the prototype of a special chamber or mini farm for investigating crop growth in highly enclosed environments. The chamber will beused for testing different ty~s of crops along with certain technological devices (lighting and nutrient del ivery systems; and sensor, monitoring,and control devices). According to NASA, previous attempts with this type of technology have produced “world record yields” ( 192). Severalaquiculture tanks are being operated and tested at Ames Research Center for identifying types of fish (e.g., tilapia) and other aquatic animalsthat can serve as a food source for human consumption, and as pr(~essms of inedible biomass into products useful for crops.

14 other t~hnologies or engineering c(}ncepts that NASA might als~~ consider include the Phase Catalytic Ammonia Mm)Val and kWiped-Film Rotating Disk Evaporator.


m

■

■

●

m

●

Pyrolysis-Thistern uses intense

commercially available sys-heat to treat hazardous waste

in the absence of oxygen. To evaluate its poten-tial in controlled ecological life support strate-gies, NASA plans to test conventional andmore advanced pyrolysis technologies (e.g.,pyrolysis technology assisted by microwaveradiation) by themselves or in combinationwith incineration.Wet oxidation-Wet Oxidation, unlike inciner-ation, which requires wastes to be sufficientlydried prior to treatment, involves the combus-tion of either a dilute or a concentrated wasteslurry at high temperature and pressure. Inaddition to reducing waste volume, wet oxida-tion allows the recovery of water and nutrientmaterials. According to NASA, a small proto-type for space application already exists.Supercritical water oxidation-This technolo-gy combines high temperature and pressure tocreate an environment—supercritical—inwhich organic and inorganic compounds pres-ent in wastes become highly soluble, reducingtheir complex chemical structure to their mostbasic forms: carbon dioxide, water, and salts.Studies are needed to evaluate means to preventpossible corrosion and clogging of systemcomponents prior to the actual deployment ofthis technology.Electrochemical oxidation—This technologyis designed to treat organic compounds at ambi-ent temperature and pressure with the assist-ance of electrochemical- and ultraviolet-gener-ated chemicals, such as ozone. Near term use isnot possible because the technology is still inits early phase of development.Plasma-arc incineration-This treatment proc-ess involves the passage of waste materialsthrough a thermal plasma field to reduce theirchemical compounds to more basic compo-nents such as hydrogen, carbon monoxide, andash. Because the technology is only in its pilot-scale research stage, additional work is re-quired before it can be applied to NASA’s fieldprograms in Alaska and Antarctica.Composting or microbial bioprocessing—Thistype of technology employs microorganisms to

degrade organic waste under near-ambientconditions and in the presence or absence of ox-ygen. In addition to volume reduction, com-porting technologies reduce organic wastes to:1) carbon dioxide, water, and microbial bio-mass when oxygen is present; or 2) methanegas and generally smaller microbial biomass inoxygen-starved processes. Application of thistechnology thus far appears limited because ofits inability to break down slurries and solidmaterials completely.

Life Support Research Testbed inBarrow, AlaskaNASA, in cooperation with various Alaskan orga-nizations (i.e., Alaska Science and TechnologyFoundation, University of Alaska, Native corpo-rations, and the private sector) is planning to testone version of its multi system approach at the Na-tional Arctic Research Laboratory in Barrow,Alaska (96,72,196). This test is expected byNASA officials to generate scientific informationuseful for supporting future use in rural Alaskanvillages and other polar regions of the world, aswell as for developing an educational outreachprogram.

Located adjacent to the kitchen of the NationalArctic Research Laboratory in Barrow, the testbedis planned to consist of only a modularized cropproduction chamber equipped with an advancedwater recovery system. The capability to processhuman waste will be added once one of the treat-ment technologies mentioned above is deter-mined as appropriate for use. Once the entire sys-tem is deployed, scientists will have theopportunity to investigate its market potential andadaptability in remote communities where sanita-tion problems continue to exist.

Antarctica Analog ProjectThe Antarctica Analog Project is a cooperative ef-fort between NASA and the National ScienceFoundation to use advanced food production(crop production and aquiculture) systems, waterrecycling methods, and human waste processingtechnologies now undergoing development and


SOURCE David Bubenheim, Chief Scientist, CELSS Research and Technology Development, Advanced Life Support Division, NASA Ames Re-search Center, personal communication, Jan 25, 1994

testing. At present, most advanced technologies tosupport researchers stationed in the South Pole arein their initial stages of project development.NASA researchers are currently identifying allrelevant design and performance characteristicsassociated with crop growth, aquiculture, andwaste processing technologies. Evaluation of pi-lot plant studies is scheduled for sometime in1995 and 1996 at the South Pole, with deploymentof a full-scale system (figure 5-9) by the year2,000 when construction of a new South Pole sta-tion is planned for completion (96,192,235).

When installed, the final Antarctic AnalogProject is expected to be fully integrated with theinfrastructure of the research station and to consistof a minifarm, a park, a food production system

(for growing fish and vegetables), and water re-covery and recycling (figure 5-10). Treatment ofhuman waste will be provided by one of thetechnologies described above once it is success-fully demonstrated for use (94, 192, 235). Lessonslearned from this research may be applicable in re-mote areas of Alaska (96,192, 309).

| NASA’s Space Shuttle Orbiter WasteManagement System

The technology used by NASA to collect sanitarywaste during space missions is commonly knownas the Space Shuttle Orbiter Waste ManagementSystem (figure 5-11 ). The primary purpose of thistechnology is to safely collect and store urine, hu-


.

SOURCE David Bubenheim, Chief Scientist, CELSS Research and Technology Development, Advanced Life Support Division, NASA Ames Re-search Center, personal communication, Jan 25, 1994

man waste, and wash water generated duringspace flight for treatment upon the shuttle’s returnto earth. The major components of this waste man-agement technology are a urine collection systemand a sewage collection-storage system. The sys-tem is highly specialized, very costly, and de-signed for a short-duration, specific mission. Onlycertain design concepts and unique features maybe applicable to the problem of providing ade-quate sanitation in rural Alaska.

Urine Collection SystemTo collect urine, air is drawn from the urinalthrough the piping, and into a fan/pump separatorwhose rotating and pumping action separatesurine from air prior to its storage in a pressurizedwastewater tank (90,3 10). Because the lack ofgravity prohibits the use of standard urinals, theurinal in the Orbiter waste management system isdesigned with clear plastic funnels (straight coni-cal design for male use; oval in shape for use byfemale astronauts) directly connected to theplumbing system (90,3 10).


To avoid the clogging and airflow loss problemcaused by drawing debris into the pump/fan sepa-rator, which was experienced in early spaceflights, NASA engineers fitted the base of the uri-nal with replaceable filtering screens (310). Thepumped air used to transport urine through theplumbing is subsequently treated by odor andbacteria filters, and returned to the cabin. Drainwater and wash water are stored in a relativelysimilar fashion (310).

One of the central components of NASA’swaste collection and storage technology is thepump/fan separator because it is the system re-sponsible for: 1 ) providing suction airflow neededfor transporting urine and feces; 2) separatingwastewater from transport air; and 3) pumpingwastewater into the pressurized holding tank.

Sewage Collection/Storage SystemNASA’s space waste management technologywas originally designed to use forced air to pushwaste into a commode tank where a rotating sling-er (a wheel with 10 tines rotating at 1,650 rpm15)breaks up and stabilizes the waste before storing itin the commode’s tank. After defecation occurs,the user actuates the commode handle to close theslide valve. The fecal material is then stabilizedand dried by vacuum action, thus rendering thewaste odorless. The air that was used to pushwaste into the commode tank is filtered by debris,odor, and bacteria filter systems and recirculatedto the cabin.

The clogging of filters and loss of airflowcaused by fine, dried fecal material experiencedduring heavy toilet usage in early flights often re-sulted in poor waste separation, incomplete trans-port into the storage tank, and inadequate sanitaryconditions in the cabin where such fecal particlesfrequently escaped. The slinger was subsequentlyremoved and replaced with a bag liner that oper-ates like a vacuum cleaner bag: it retains bacteriaand waste particles inside it without preventing airfrom passing through (90).

The rapid filling of the bag liner system withtissue paper as opposed to human waste-causedby the absence of gravity, which, in turn, pre-cludes the separation and dropping of human fecesfrom the body—forced NASA engineers to ulti-mately replace the bag liner with a feces compac-tor. By rotating a movable vane located inside thetank, the stretchable fabric material, attached tothe movable vane at one end and to a stationaryvane on the other, is forced to sweep the interior ofthe ellipsoidal waste commode and compact thewaste. Air drawn through the commode is treatedand returned to the cabin. Compaction of waste bythis currently used technology is required only ev-ery fifth or sixth day of operation.

| NASA’s Extended Duration OrbiterWaste Management System

Another very specialized design may be useful forits concepts and unique features. NASA is testinga new waste collection technology known as theExtended Duration Orbiter Waste ManagementSystem (figure 5-12) that uses a mechanical pistoncompactor and disposable bags with plastic lids.Prototypes of this less expensive and easy tomaintain waste collection system are being builtand scheduled for use in future space flights(90,191 ,239).

The Extended Duration Orbiter waste collec-tion system is designed to be used as a convention-al toilet. Its size (12 inches long, 16 inches wide,and 35 inches high), weight (60 pounds), and lowpower consumption makes this technical ap-proach, according to its developers, one of themost promising for future extended space use(239). One particular advantage of this system.over the currently used one is its capability to meetthe sanitation needs of up to seven astronauts for aperiod of 18 to 30 days (90).

During its use, proponents indicate, wastes (in-cluding feces, urine, and tissue paper) disposed inthe bowl are contained inside a cylindrical bag thatpermits air to flow through. By applying a load of

1 S Revolutlon5° per minute.

F’il,/ g’ &

Chapte 5: Alternative Sanitation Technologies I 89

%!-=

L.—

aac.=3

/ f u


a

s

Interfaces /

SOURCE H J Brasseaux Jr, H E Winkler, J D North, and S P Orlando, “The Extended Duration Orbiter Waste Collection System, ” SAE Technica/Paper Series, No 901291, 1990

about 100 pounds, the compactor travels down thetransport tube pushing the waste-containing bagand its lid to the bottom of the collection canisterwhere they are compacted. The rigid collar andwiper-like design of the lid are used to scrape anywaste that may have adhered to the walls of thetransport tube. The bag is then left behind as partof the stored waste material.

Once the piston returns to its original position.the user places a fresh bag in the toilet for the nextuser before closing the toilet seat and 1 id. Replace-ment of collection canisters in the proposed Ex-tended Duration Orbiter system is expected totake place only after an average of 30 uses. Test re-sults from recent space flights show the individual

bag collection system to be relatively cleaner thanthe commode system currently in use by theshuttle (21 2).

| The “Self-Contained Home” SystemAccording to its designer, the Self-ContainedHome technology has been conceived to addressin a cost-effective manner the most basic needs ofNatives in rural Alaska: housing, heating, and san-itation. As planned, the technology will consist ofan insulated house (36 feet by 38 feet) speciallydesigned for the Arctic environment and servedwith a heat/cook stove, a self-generated water sys-tem, and an Arctic toilet system in which human

Chapter 5: Alternative Sanitation Technologies| 91

waste is treated with recycled heat. Made of steel,the heat/cook stove-considered the cornerstoneof this system-can be operated with wood, coal,or fuel (92,93).

The Self-Contained Home appears to be poten-tially useful in addressing more than the waste dis-posal needs of Native communities in rural Alas-ka, but because this technology is still in itsdevelopmental stage, field studies would have tobe undertaken to ascertain the actual applicabilityof this approach.

SUMMARY OF TECHNOLOGYISSUES AND NEEDSAll of the alternative technologies describedabove require some degree of development, test-ing, and evaluation before they could be chosen asa proven system with satisfactory performance en-sured. Identifying and developing appropriatetechnologies, while meeting safety and reliabilitystandards within cost constraints, constitute themajor challenge for designers and developers ofany sanitary technology in the Arctic. In yearspast, most Federal and State agencies providedrelatively little support for the basic engineeringand environmental research required to producethe data necessary to design and implement spe-cific technologies. This deficiency resulted in ashortage of information in several areas, such ashydrology (e.g., snow surveys), soil (e.g., perma-frost), ice research, and climate and natural haz-ards (8). Considerable progress was achieved inthese areas during the 1980s, particularly with theconstruction of the Alaskan oil pipeline and theinstallation of piped sanitation systems at majoroil industry facilities in Pruhdoe Bay. These ad-vanced piped systems cannot be applied in mostvillages, however, because of high construction,operation, and maintenance costs.

Very few alternative sanitation methods havebenefited from field demonstration tests in ruralAlaskan communities in the past. Most of the at-tempted evaluations failed. The failures werelargely the result of limited or inadequate guid-ance provided to Natives by technology develop-ers. With the exception of certain comporting

technologies, the Office of Technology Assess-ment (OTA) found no long-term effort dedicatedto the demonstration of alternative sanitationtechnologies.

Even today, relatively little information existson the application of alternative sanitationtechnologies in environments such as that of ruralAlaska. Adopting these systems without first ex-ploring the factors that will make their applicationin Native villages successful is risky and subjectto failure. In many Alaskan villages, there arephysical, social, and economic conditions notcommonly found in other areas of the UnitedStates. Such conditions include limited drainageand poor soil conditions caused by discontinuouspermafrost, seasonal variations in the quantity andquality of the water available, and high costs ofelectricity and fuel. Unfortunately, programs tofund field demonstrations of alternative technolo-gies, to coordinate Federal and State technologyprograms and policies, and to establish a forum forthe advancement of innovative sanitation systemsdo not exist.

Alternative sanitation technologies must beevaluated prior to their actual use among Nativecommunities and must be designed to accommo-date the unique Alaskan environment, includingfactors such as:

■

m

Permafrost—This is of great importance in theengineering and design of structures and sys-tems, particularly in ice-rich, fine-grained soil,where the ground forms an extremely strongand stable foundation material when frozen butan extremely weak foundation when thawed.The location, depth, and extent of permafrostmay preclude the selection of certain sanitationsystems due to its influence on local soil condi-tions, groundwater table, and seasonal flood-ing.Availability of water—Adequate availabilityof water is a key consideration in the selectionof flush toilet systems because without it, sew-er, septic tank, and truck haul holding tank sys-tems cannot perform properly. (Water is alsoextremely important for practicing hygiene. )Piped water is normally incorporated into


piped sewerage projects because the two sys-tems are mutually dependent; however, theyalso lead to increased water consumption, thuscreating a need for additional disposal capacity.The interior region of Alaska is generally sup-plied with water and contains large areas of wetmuskeg and lakes, with significant snowmeltrunoff and river drainage. In the Arctic region,however, a myriad of shallow lakes disguise thefact that water supplies are actually very lim-ited for supporting sanitation technologies thatconsume large amounts of water.

■ Household size and design—Identifying thenumber of persons residing in each house forwhich use of a particular technology might beplanned, as well as recognizing the perceptionthey have about that particular technology, isimportant in estimating in advance the technol-ogy’s potential for success. Consideration ofhousehold size and design is also important indetermining waste volumes to be treated ormanaged, projecting future system expansions,and estimating costs over extended periods oftime.

■ Technical training—Training Natives in howto operate sanitation technologies has not al-ways been successful. The reasons for suchfailure have been primarily the use of inap-propriate off-the-shelf packaged training pro-grams and the increasing shortage of technicalassistance from Federal and State agencies. Toavoid these failures, there is a need to developprograms that are culturally sensitive and prac-tical, and that focus on the realities of the partic-ular village in which the technology will be ap-plied. Examples of these include locallimitations in management capability, leader-ship, and fiscal responsibility. Identifying theextent of the external financial and technical as-sistance that will be needed once the technolo-gy is installed will be also useful.

- Native community involvement—Althoughthe intrusion of Western culture has sometimesmet with resentment, many Natives continue tobelieve that the main source of resentment hasemerged primarily from being told by outsiderswhat to do and how to do it, and rarely being in-

cluded in the development of solutions to localsanitation problems. Encouraging and support-ing continued village participation in the selec-tion and implementation process are extremelyimportant for ensuring a strong perception ofcommunity ownership over the project-—anelement crucial to the successful application ofany technology.

■ Local village economy—The majority of Na-tive communities of rural Alaska rely almostcompletely on transfer payments and subsidiesfrom Federal and State agencies to operate ba-sic village programs, including sanitation proj-ects. Despite the increasing demand for newsanitation projects, the serious economic diffi-culties faced by Native villages with existingsystems raises the need to avoid installing simi-lar complex technologies in communities withfew economic and technical resources to oper-ate them. Consequently, addressing the wastesanitation problem in Alaska’s Native commu-nities requires steps that focus on identifying,demonstrating, and adopting more cost-effec-tive alternatives to honey buckets. Selectingtechnologies that deliver sanitation with littleadditional adverse impact on the limited or de-clining local economies is needed.

■ Actual costs to Native village residents--Inrecent years, Federal and State agencies havefocused primarily on providing conventionaltechnologies that require high capital costs anda significant degree of advanced engineering.Their efforts to assist Native villages financial-ly with the operation and maintenance of theseprojects have been rare. This, and the failure totrack community expenses for O&M, have lim-ited the information available today for esti-mating the actual costs of sanitation projects.

Actual cost data for estimating life cycle costsof complete systems in Alaskan Native communi-ties do not exist. Accurate life cycle cost compari-sons of alternative and conventional systems arenot possible. Not only does this impair the evalua-tion of each system’s cost-effectiveness but it pro-hibits agency officials from making valid esti-mates of the overall economic impact of each

Chapter 5: Alternative Sanitation Technologies| 93

technology on the community. There are no dataon the potential economic savings by communi-ties that might employ alternative technologiesrather than conventional ones. Savings associatedwith the use of alternative sanitation technologiescould include, for example, eliminating local ex-penses associated with building and maintaining asewage lagoon, reducing the community waterand energy consumption, reducing the need forcertified facility operators, and reducing equip-ment repair or replacement costs. Limited dataalso prohibit the evaluation of the potential im-pacts of using alternative systems that do not de-liver potable water to the home.

Technology selection decisions to date havebeen based on a capital planning process that takesinto consideration the type and size of the sanita-tion facility to be installed, the financing processto follow, and the methods by which costs will berecovered. This process, however, is largely lim-ited to the construction of conventional technolo-gies and does not allow for a comparison of con-ventional and alternative approaches based ontotal life cycle costs. Only minimal attempts havebeen made to formally incorporate existing alter-native sanitation systems into the technologyselection process currently in place.

CONCLUSIONAlternative sanitation technologies, such as com-porting, electric, and propane toilets, appear to bean improvement over honey buckets because theyreduce the possibility of users coming in contactwith human waste and they may reduce overall,

long-term costs. Not only do these technologieseliminate the need for a sewage lagoon to hold thewastewater for treatment, as in a conventionalpiped or haul system, they may also yield a by-product that is generally more environmentallysafe or easier to handle. These alternative ap-proaches, however, do not provide the potable wa-ter that is needed to practice good sanitation.

Certain of the advanced engineering systems orconcepts presented in this chapter appear poten-tially beneficial. Some, as in the case of NASA’slife support systems, still require substantial de-sign modifications, adaptation, or testing beforethey can actually be considered for waste treat-ment in Native Alaskan villages. Others, like En-tech’s thermal oxidation system, might be appli-cable to treating human waste, but they requiretesting and evaluation.

Conditions in Native villages (i.e., inadequatewater supply, poor soil drainage. permafrost, un-acceptable topography, high seasonal floodingpotential, and weak local economies) appear to fa-vor the application of less costly and complex sys-tems. With the exception of the limited testingconducted on certain comporting methods, mostalternative technologies have not been tested forthe treatment of human waste in the harsh environ-mental conditions typical of rural Alaska. Devel-opment of a more comprehensive technologyevaluation and selection approach capable of sup-porting demonstration, applied research, andapplication of innovative technologies is still nec-essary.

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Alternative Sanitation Technologies