HOW REMOTE TOILETS WORK (OR FAIL TO)And what they should really be doing

Geoff Hill, PhDSustainable Summits Conference Golden, CO

Waterless Toilet Overview Comparison

Elbow Lake, ABCampground, open 3 months per yearUse/yr: 50002 stall - 2 Composting ToiletsAnnual O&M cost: $2660O&M Freq: weeklyCost per use: $0.53OSHA Exposure Events/yr: 33Material removal: every year (dump)

Faverges, FranceRoad Side, open 12 months per year

Use/yr: 200001 Stall – Urine Diverting + Vermicomposting

Annual O&M cost: $700O&M Freq: yearly

Cost per use: $0.035OSHA Exposure Events/yr: 3

Material Removal: every 10-20 years (dump)

Outline• Waste Paradigm• Compost – what it actually is• Remote Site Challenges• Types, Objectives, Evaluation of Remote Toilets• Human Waste Composition & Production• Source Separation• Urine Diversion• Performance of Urine Diversion vermicomposting toilets• Future Direction

Flush Toilet• Homes in the Western world

• Water (cheap / limitless)• Power (cheap / limitless)• Onsite labor (cheap, home owner)• Nutrients needs (garden, lawn)• We FLUSH it away

• Waste Management Paradigm• Toilet #1 invention for human health• Water as vehicle – everything removed at WWTP

Compost from biosolids in USA• Biosolids extracted from WWTP – burned, land applied, or

composted• Public operations are held to EPA 503 rules, thermophilic

engineered process for degrading and sanitizing waste• 5 turns in 15 days, >55C, fecal coliform testing to assure process,

• Very rigorous and challenging• Done at centralized facilities

• Still very difficult to make profitable and worthwhile

Remote sites• No power / solar power• No water • Limited / expensive labor• Cold• No use for nutrients or organic

matter

Types of Toilets at Remote Sites• Pit

• Dig hole (6-10’ deep), fill up, cap, dig another.• Composting

• Buy unit, users add wood, ‘service’ weekly, blackwater leaches, dump solids onsite yearly (or pack-out)

• Vault (concrete or plastic barrel)• Buy precast unit, pump yearly, remove to WWTP

• Incinerating (very few – private)• Urine Diverting Vermicomposting (France)

• Not covering dispersed• Pack-out• Cat hole

Objective of These Toilets• Pit

• Lowest cost regardless of human health & environment• Composting

• Make compost, regardless of O&M cost & safety• Vault (concrete or plastic barrel)

• Least environmental impact, safety, O&M cost• UDVCT

• Lowest life cycle cost O&M, acceptable environmental impact, and high health & safety standard

Pit Toilet In Ground Water: World Heritage Site, BC

Pits• Pits can be found years later – no

decay • Many toilets dug into ground water• With 1m unsaturated soil

• Viral pathogens can travel 3000m• Hepatitis A, Polio, Astrovirus, Calcivirus,

Rotavirus, Norwalk, Coxsackievirus, Echovirus

Sources:WHO Funded: “Guidelines for Assessing the Risk to Groundwater from On-Site Sanitation”, British Geological SurveyMoore, C., 2010. Institute of Environmental Science and Research (N.Z.) Staff. Guidelines for separation distances based on virus transport between on-site domestic wastewater systems and wells. ESR Communicable Disease Centre, Porirua, New Zealand.

Pits• Treatment paradigm

• Not effective• Dumps in our parks?

• Waste Management Paradigm• Not safe• Virus travel very far• Very hard to detect (few labs culture viruses)

• NPS – should all be replaced• With…..

Composting toilets• Don’t compost shit at home…

• Why compost shit in the woods?

• Tried to failure dozens – hundreds of times

Composting Toilet Photo Tour

Composting toilets (CTs): a misnomer• PhD + 5 peer review publications

• 4 brands, 12 sites, 16 chambers, 100+ samples

• 0/16 chambers pass NSF Standard 41• 0/16 processes meet EPA 503 regulations

• None heat up more than 10C above ambient• 0/100 samples meet definition of compost

• Stability, maturity, smell• Raw fecal matter no different from CT end-

product (E.coli, volatile solids, stability)• All continuous flow

• Effective residence time: 1-2 days

6yr old ‘compost’

2 outcomes• Ammonification toilet

• Primarily urine – ammonia & pH escalate – inhibits all life• Not effective enough to reliably sanitize• Many campgrounds and trailheads

• Pathogen brew pot• Primarily fecal matter• UBC CK Choi – Flagship of composting toilets, maintained by paid

personnel every day.• >100,000 E.coli in 5yr old material (E.coli breeding ground)

Composting Toilets as Waste Management (typical 3000 user site)• $2665/yr to maintain• 33 occupational exposure events / yr (face close to

fecal)• Effective?

Vault Toilets - Barrel• True waste management perspective• Terribly expensive and hazardous to operate• $0.30 to $1.00 per use• Requires an operator to change barrels

Human Waste Production / Composition

• Urine• 160-200ml per use• 80% of plant nutrients (NPK)• Zero heavy metals• Zero pathogens • Self sanitizing (storage)• Flows by gravity

• Fecal matter• 80-100g per use• 20% of plant nutrients• 100% of heavy metals• 100% of pathogens (106-8bacteria,

helminth, viral, protozoan)• Doesn’t flow

Source Separation• For maximum value & least cost ‘waste management’• Waste Management BMP• Lets apply to wilderness waste• Human waste = urine + fecal (2:1)

Urine Diversion Retrofits (2)• Ecovita 501 Privy• Clogged within a week of installation

Urine Diverting Vermicomposting (UDVCT)

• Ecosphere Technologies & Ecodomeo (France)• No bulking agent

UDVCT

End-Product Waste Management

Stable – Very Stable O&M costs/yr = $273

No odor Exposure events/yr = 3

<200 CFU/g E.coli Dry matter reduction = 40%

Lots of trash Emptied every 10-20 years

UDVCT vs CTUDVCT CT Comparison

O&M costs/yr = $273 $2665 10x

Exposure events/yr 3 33 10x

Dry matter reduction -40% +300% Almost 10x

Disposal Emptied every 10-20 years

Every 6mo – 2 yrs

5-20x

E.Coli <200CFU/g 104-106 CFU/g 100x lower

North American Implications• Step 1: divert urine

• Gravity manage to septic field 66% of daily mass• Step 2: don’t add bulking agent• Step 3: look and see what’s eating local horse manure

(naturally source separated) and put it into fecal matter & toilet paper

• Step 4: don’t touch the poo, leave it for as long as possible

• Step 5: budget a decadal line item for removal and disposal

Slugs in the Pacific Northwest

Step 1: Divert Urine (the hard step)• Behavior• Ecovita seat – private only• Mechanical (Toilet Tech Solutions)

Behind-the-Wall + Pedal Power Below-The-Floor + Door Power

TTS Below-the-Floor

Glacier Bay National Park, AK

TTS Behind-the-Wall

Glacier Bay National Park, AK

Neat and Cool, Squamish Smoke Bluffs, B.C.Sponsored by MEC, District of Squamish, andClimate action network.

$4000 plus or minus