Water Purification for Nepal Trekking: Methods, Costs & Recommendations

Waterborne illness is the single most common health problem on Nepal treks. Every year, hundreds of trekkers cut their journeys short because of diarrhea, vomiting, or debilitating stomach cramps caused by contaminated water. Unlike altitude sickness, which can often be managed with slow acclimatization and medication, a severe gastrointestinal infection at 4,500 meters can turn a dream trek into a medical emergency.

Proper water purification is not optional. It is essential for every trekker, every day, at every altitude. Whether you are heading to Everest Base Camp, the Annapurna Circuit, or a remote route in Dolpo, you need a reliable plan for making water safe to drink.

This guide compares every viable purification method available to trekkers in Nepal, provides honest cost analysis over the duration of a typical trek, and recommends specific products and strategies. We also address the environmental crisis that bottled water has created on Nepal's most popular trail corridors and explain how individual purification eliminates the problem entirely.

What this guide covers:

• Five proven water purification methods with product recommendations
• Detailed cost comparison over a 14-day trek
• Route-specific advice for EBC, Annapurna, Manaslu, and remote treks
• The environmental case against bottled water
• The best combined strategy used by experienced trekkers and guides

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Why You Can't Drink Tap Water in Nepal

Nepal's water supply, from Kathmandu to the highest mountain villages, is not safe for direct consumption by anyone unaccustomed to the local microbiome. Understanding why is the first step toward protecting yourself.

Contamination Sources

Water in Nepal is contaminated through multiple vectors:

• Animal waste: Yaks, dzopkyos, mules, and livestock graze freely along trekking routes. Their waste runs directly into the streams and rivers that feed village water supplies. Even at altitudes above 4,000 meters, yak herds are omnipresent along popular corridors.
• Agricultural runoff: In lower-altitude regions (below 3,000m), fertilizers and pesticides from terraced farmland leach into groundwater and surface water sources.
• Inadequate sanitation: Most mountain villages lack modern sewage treatment. Pit latrines are positioned near water sources, and during monsoon months, contamination spreads rapidly through flooding and saturated soil.
• Shared water channels: Irrigation canals that supply drinking water often serve multiple purposes, including laundry, bathing, and livestock watering.

The High-Altitude Myth

One of the most dangerous misconceptions among trekkers is that water from high-altitude streams is "pure" because it comes from snowmelt or glaciers. This is false. Even crystal-clear streams at 5,000 meters can harbor pathogens:

• Giardia cysts survive in cold water and at high elevations
• Yak and other animal waste is deposited directly into streams at every altitude on popular routes
• Glacial meltwater passes through soil and rock that may contain bacterial contamination
• Human waste from campsites and poorly managed toilet facilities contaminates nearby water sources

Tea House Water: Not Always Safe

Many trekkers assume that water provided at tea houses has been properly boiled and is safe. This is not always the case:

• Some tea houses boil water to a rolling boil (sufficient for purification), but others heat it only until steaming, which does not reach temperatures high enough to kill all pathogens.
• Storage containers may introduce recontamination after boiling. Water stored in jugs or tanks that have not been properly cleaned can harbor bacteria even if the water was originally safe.
• "Filtered" water at tea houses varies enormously in quality. Some filters are well-maintained; others have not been cleaned or replaced in months.
• Water used for cooking (dal bhat, soups) is generally safe because it reaches sustained high temperatures. Water served as "drinking water" or used to wash dishes and cups may not be.

The Plastic Bottle Problem

Buying bottled water on the trail has become a serious environmental disaster:

• On the Everest Base Camp route alone, an estimated 600,000 or more plastic bottles are discarded annually
• Plastic waste is burned (releasing toxic fumes), buried (contaminating soil), or simply left on the trail
• The price of bottled water increases dramatically with altitude: NPR 100 at Lukla, NPR 300-500 at Gorak Shep
• Bottles must be carried up by porters, adding to their already heavy loads
• Nepal has no effective high-altitude recycling infrastructure for the volume of waste generated

Using your own purification system eliminates 3 to 5 plastic bottles per person per day. Over a 14-day trek, that is 42 to 70 fewer bottles entering Nepal's fragile mountain environment.

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Method 1: UV Light Purifiers (SteriPEN)

UV purification is the preferred method among experienced tea house trekkers for its speed, effectiveness, and convenience. These devices use ultraviolet-C light to destroy the DNA of bacteria, viruses, and protozoa, rendering them unable to reproduce and cause illness.

How It Works

UV-C light at a wavelength of 254 nanometers penetrates the cell walls of microorganisms and damages their nucleic acids. A single treatment cycle kills or inactivates 99.9% of bacteria (including E. coli and salmonella), 99.9% of viruses (including hepatitis A and norovirus), and 99.9% of protozoa (including giardia and cryptosporidium). The process takes 90 seconds for one liter of water and leaves no chemical taste or residue.

Recommended Models

SteriPEN Ultra — The most popular choice among Nepal trekkers. Rechargeable via USB, treats up to 8,000 liters per lamp life. USB charging means you can recharge from a power bank, solar panel, or tea house outlet. Weight: 140 grams. Price: $70-90.

SteriPEN Classic 3 — Uses CR123 batteries instead of USB charging. Good for trekkers who prefer replaceable batteries over recharging. Treats up to 8,000 liters. Heavier than the Ultra but eliminates charging dependency. Weight: 185 grams (with batteries). Price: $50-70.

CrazyCap 2.0 — A water bottle with built-in UV-C purification. Convenient all-in-one design, but smaller treatment volume and less field-proven than SteriPEN products. USB rechargeable. Weight: 340 grams (empty bottle). Price: $70-100.

Pros

• Fast: 90 seconds per liter is the fastest purification method available
• No chemical taste: Water tastes exactly as it did before treatment
• Lightweight: SteriPEN Ultra weighs just 140 grams
• Rechargeable: USB models charge from power banks, making it sustainable for long treks
• Proven effectiveness: Independent lab testing confirms 99.9% pathogen kill rate
• Simple operation: Stir the light in the water, wait for the indicator, done

Cons

• Requires clear water: UV light cannot penetrate turbid or cloudy water. If the water has visible particles, you must pre-filter it through a bandana, coffee filter, or dedicated pre-filter before UV treatment
• Battery/charging dependency: Electronic devices can fail. Cold temperatures at altitude reduce battery performance. You must have a charging solution or backup batteries
• No particle removal: UV treats biological contaminants only. It does not remove sediment, heavy metals, or chemical pollutants
• Electronic failure risk: Though rare, any electronic device can malfunction in the harsh conditions of high-altitude trekking (cold, moisture, impacts)
• Indicator trust: You must trust the device's indicator that treatment is complete, as there is no visual confirmation the water is safe

Cost Analysis

• Upfront cost: $50-100 for the device
• Ongoing cost: Approximately $0.02 per liter (electricity for charging)
• 14-day trek cost: $60-100 total (device purchase, essentially free per liter after that)

Best For

Tea house trekkers on popular routes where charging is available. If you are trekking the Everest Base Camp route or Annapurna Circuit, a UV purifier paired with a portable power bank is the most efficient primary purification method.

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Method 2: Pump and Gravity Filters

Physical filtration forces water through microscopic pores that physically block pathogens and particles. These systems range from simple squeeze filters to gravity-fed setups that purify large volumes hands-free. They are the method of choice for trekkers who want independence from batteries and charging infrastructure.

How It Works

Water is pushed or pulled through a filter membrane with pore sizes small enough to trap bacteria (0.2 microns) and protozoa (1 micron and larger). Some advanced filters use hollow-fiber technology with thousands of tiny tubes, each perforated with pores that allow water molecules through but block larger organisms. The result is mechanically purified water with particles and sediment removed.

Recommended Models

Sawyer Squeeze — The workhorse of backpacking filtration worldwide. Weighs just 85 grams, filters down to 0.1 microns (removes bacteria and protozoa), and attaches directly to standard water bottle threads or the included squeeze pouches. Rated for 100,000 gallons before replacement. Backflush syringe included for field maintenance. Price: $30-40.

Katadyn BeFree 1.0L — A soft flask with an integrated filter that collapses when empty. Incredibly fast flow rate (2 liters per minute), 0.1-micron filtration. Lightweight at 63 grams. The soft flask design saves space. However, it is less durable than the Sawyer and the proprietary flask cannot be replaced with standard bottles. Price: $40-50.

Platypus GravityWorks 4.0L — A gravity-fed system ideal for groups. Hang the dirty water reservoir, and gravity pulls water through the filter into a clean reservoir below. No pumping, squeezing, or effort required. Filters 4 liters in approximately 2.5 minutes. Weight: 310 grams. Best for group treks or base camp use. Price: $50-60.

MSR Guardian Purifier — The only pump filter that also removes viruses (0.02-micron pore size). Military-grade construction, self-cleaning with every pump stroke. Heavy at 490 grams and expensive at $350, but it is the only mechanical device that is a true purifier rather than just a filter. Best for remote treks where water quality is unknown and no backup method is available.

Pros

• No batteries required: Purely mechanical operation means no charging, no electronic failures
• Works on cloudy water: Physical filtration removes particles that make water turbid, something UV cannot do
• Filters sediment and particles: Improves both the safety and clarity of water
• Long lifespan: The Sawyer Squeeze is rated for 100,000 gallons, effectively a lifetime of trekking
• Immediate availability: No wait time. Filter, drink, move on

Cons

• Most do NOT remove viruses: This is the critical limitation. Standard backpacking filters with 0.1 or 0.2-micron pores block bacteria and protozoa but allow viruses to pass through. Viruses are as small as 0.02 microns
• Freezing risk: If water inside the filter freezes, expanding ice can crack the hollow fibers, invisibly compromising the filter's integrity. A frozen filter must be considered failed and replaced
• Clogging: Dirty water sources clog filters faster, reducing flow rate. Backflushing restores flow but adds maintenance
• Weight (gravity systems): Pump and gravity systems weigh 300-500 grams, more than UV or chemical options
• Slower for volume: Squeeze filters require physical effort; gravity systems require setup time and patience

Cost Analysis

• Upfront cost: $30-60 for most filters ($350 for MSR Guardian)
• Ongoing cost: Approximately $0.01 per liter (replacement pouches occasionally)
• 14-day trek cost: $30-60 total (device purchase, negligible ongoing cost)

Best For

Independent trekkers, camping treks, and anyone who wants battery-free reliability. Particularly suited for off-the-beaten-path routes where charging facilities are unavailable and water sources are silty or glacial. Always pair with chemical backup for virus protection.

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Method 3: Chemical Treatment (Tablets and Drops)

Chemical purification uses disinfecting agents to kill pathogens in water. It is the lightest, cheapest, and most reliable backup method available. Every trekker in Nepal should carry chemical treatment regardless of their primary purification method.

Chlorine Dioxide (Aquamira, Katadyn Micropur)

Chlorine dioxide is the gold standard of chemical water treatment for trekkers. Unlike simple chlorine, chlorine dioxide is effective against bacteria, viruses, AND protozoa including the notoriously resistant cryptosporidium.

Aquamira Water Treatment Drops: A two-part liquid system (Part A and Part B) that you mix together, wait 5 minutes for activation, then add to your water. Treats 30 gallons per kit. Very effective, minimal taste when used correctly. Weight: 85 grams. Price: $12-15.

Katadyn Micropur MP1 Tablets: Individual tablets, each treating 1 liter. Extremely convenient: drop one tablet in, wait, drink. No mixing required. Each box contains 20 or 30 tablets. Weight: 30 grams for 20 tablets. Price: $10-14 for 20 tablets.

Treatment time: 15 minutes for bacteria and viruses; 30 minutes for giardia; 4 hours for cryptosporidium. The 4-hour wait for crypto is the major drawback of this method.

Iodine Tablets

Iodine has been used for water purification for decades and remains effective against most bacteria, viruses, and giardia. However, it has significant limitations that have made it less popular in recent years.

Potable Aqua Iodine Tablets: The most widely available iodine treatment. Each tablet treats 1 liter. PA+ neutralizer tablets are sold separately to reduce the iodine taste. Weight: 30 grams. Price: $8-12 for 50 tablets.

Limitations of iodine:

• Does NOT reliably kill cryptosporidium
• Produces an unpleasant metallic taste (neutralizer tablets help but do not eliminate it)
• Not recommended for continuous use beyond 3-4 weeks due to thyroid concerns
• Not recommended for pregnant women or individuals with thyroid conditions
• Effectiveness decreases in cold water (which is what you primarily encounter at altitude)

Pros of Chemical Treatment

• Lightest option: 30-85 grams covers an entire trek
• Cheapest option: $8-15 for enough treatment for 30-50+ liters
• No moving parts: Nothing to break, freeze, or malfunction
• Reliable backup: Works regardless of water clarity, altitude, or temperature
• Always available: Can be purchased in Kathmandu and in Namche Bazaar or other gateway towns

Cons of Chemical Treatment

• Wait time: 15 minutes minimum, up to 4 hours for full cryptosporidium protection with chlorine dioxide. Iodine requires 30 minutes for cold water
• Taste: Both chlorine dioxide and iodine impart some flavor to the water, though chlorine dioxide is considerably milder
• Chemical concerns: Long-term iodine use affects thyroid function. Chlorine dioxide is considered safe for extended use but some trekkers are uncomfortable with chemical treatment
• No particle removal: Like UV, chemical treatment does not filter out sediment or improve water clarity
• Temperature dependent: Chemical reactions slow in cold water, requiring longer treatment times at altitude

Cost Analysis

• Upfront cost: $8-15
• Ongoing cost: $0.03-0.05 per liter
• 14-day trek cost: $10-15 total

Best For

Every trekker, as a backup method. Chemical tablets should be in your first aid kit regardless of what primary purification method you use. They are also the optimal primary choice for ultralight trekkers who want to minimize weight and bulk.

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Method 4: Boiling Water

Boiling is the oldest and most universally effective water purification method. It kills 100% of bacteria, viruses, protozoa, and any other biological contaminant. It is the gold standard against which all other methods are measured.

The Science

Heating water to a rolling boil (100 degrees Celsius at sea level) for one minute kills all pathogenic organisms. The WHO confirms that even at high altitude, where water boils at a lower temperature (approximately 85 degrees Celsius at 4,500 meters, 81 degrees at 5,500 meters), pathogens are killed well below boiling point. Pasteurization occurs at 65 degrees Celsius sustained for several minutes. A rolling boil at any altitude in Nepal provides a significant safety margin.

Availability on Trek

Boiled water is available at every tea house on every major trekking route in Nepal. Prices vary by altitude and remoteness:

• Lukla to Namche (2,800-3,440m): NPR 100-200 per liter ($0.75-1.50)
• Namche to Dingboche (3,440-4,410m): NPR 200-350 per liter ($1.50-2.50)
• Dingboche to Gorak Shep (4,410-5,164m): NPR 350-500 per liter ($2.50-4.00)
• Annapurna Circuit (lower sections): NPR 80-150 per liter ($0.60-1.10)
• Annapurna Circuit (Thorong La area): NPR 200-400 per liter ($1.50-3.00)

Boiling Time at Altitude

A common concern is whether water boils at a high enough temperature at altitude. Here is the reality:

| Altitude | Boiling Point | Effective? | |---|---|---| | Sea Level (0m) | 100°C | Yes | | Namche Bazaar (3,440m) | 89°C | Yes | | Dingboche (4,410m) | 86°C | Yes | | Everest Base Camp (5,364m) | 82°C | Yes | | Camp 2 Everest (6,400m) | 79°C | Yes |

All of these temperatures are well above the 65 degrees Celsius pasteurization threshold. The WHO explicitly states that bringing water to a rolling boil at any altitude is sufficient for purification; no additional boiling time is necessary.

Pros

• 100% effective: Kills every known waterborne pathogen, no exceptions
• Available everywhere: Every tea house has the ability to boil water
• No equipment needed: No devices to carry, maintain, charge, or replace
• Familiar and trusted: No learning curve, no uncertainty about effectiveness
• Doubles as hot drinks: Boiled water for tea, coffee, soups, and instant noodles serves dual purposes

Cons

• Cost adds up: At $2-4 per liter at high altitude, consuming 4 liters per day means $8-16 per day, or $112-224 over a 14-day trek
• Fuel consumption: Boiling water consumes significant amounts of kerosene, wood, or gas. At high altitude where fuel must be carried in by porters, this environmental cost is substantial
• Wait time for cooling: Boiled water must cool before you can drink it, which can take 30-60 minutes. This is inconvenient during active trekking
• Not always genuinely boiled: As mentioned earlier, not all tea houses bring water to a full rolling boil

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Method 5: Safe Water Stations

Safe Water Stations are community-operated water refill points found along Nepal's most popular trekking corridors. They provide treated, safe drinking water at a fraction of bottled water prices, with the proceeds supporting local water infrastructure development.

How They Work

These stations use a combination of UV treatment, filtration, and sometimes chlorination to produce safe drinking water in bulk. Trekkers refill their own bottles from taps at the station, pay a small fee, and continue trekking. The stations are maintained by local community groups and supported by organizations including the Sagarmatha Pollution Control Committee (SPCC) and initiatives like Sagarmatha Next.

Cost and Availability

• Price: NPR 70-140 per liter ($0.50-1.00), significantly cheaper than bottled water or tea house boiled water at the same altitudes
• EBC route stations: Lukla, Monjo, Namche Bazaar, Tengboche, Dingboche, Pheriche, Lobuche
• Annapurna region stations: Multiple stations along the Annapurna Circuit and ABC route, concentrated in the ACAP (Annapurna Conservation Area Project) zones
• Operating hours: Most stations operate during peak trekking hours (approximately 7:00 AM to 5:00 PM), though hours vary by location and season

Pros

• Affordable: 50-75% cheaper than bottled water at the same altitude
• Environmentally responsible: Eliminates plastic bottle waste entirely
• Supports local communities: Revenue funds water infrastructure, maintenance, and local employment
• Convenient: Simple refill process, no waiting or treatment required on your part
• Professionally maintained: Stations are regularly tested and maintained to ensure water quality

Cons

• Limited to popular routes: Not available on remote treks like Upper Dolpo, Kanchenjunga, or Makalu
• Not at every stop: Even on popular routes, there are gaps between stations. You cannot rely on Safe Water Stations as your sole water source
• Seasonal closures: Some stations close during monsoon season or winter
• Occasional breakdowns: Equipment failures happen, and replacement parts may take time to arrive in remote locations

Best For

Trekkers on the EBC and Annapurna routes who want to supplement their personal purification system with convenient, cheap, professionally treated water. Use Safe Water Stations when available, but always carry your own purification as backup.

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Cost Comparison: 14-Day Trek

The following table compares the total cost of each water purification approach over a standard 14-day tea house trek, assuming an average consumption of 4 liters per day (56 liters total). This is the minimum recommended intake at altitude; many trekkers consume more.

| Method | Upfront Cost | Per Liter Cost | 14-Day Total | Plastic Bottles Generated | Weight Carried | |---|---|---|---|---|---| | Bottled Water | $0 | $1.00-2.50 | $56-140 | 56-112 bottles | 0g (buy as needed) | | Boiled Water (Tea Houses) | $0 | $0.50-1.00 | $28-56 | 0 bottles | 0g | | UV Purifier (SteriPEN) | $60-90 | ~$0.02 | $61-91 | 0 bottles | 140g | | Water Filter (Sawyer) | $30-40 | ~$0.01 | $31-41 | 0 bottles | 85g | | Chemical Tablets (Micropur) | $10-15 | ~$0.04 | $12-17 | 0 bottles | 30g | | Safe Water Stations | $0 | $0.50-1.00 | $28-56 | 0 bottles | 0g | | Recommended Combo | $40-55 | ~$0.02 | $42-57 | 0 bottles | 170g |

The Recommended Combo row reflects the strategy used by experienced trekkers: a UV purifier or filter as primary method, chemical tablets as backup, and Safe Water Stations or tea house boiled water when convenient. After the initial equipment purchase, subsequent treks cost virtually nothing for water.

The bottled water approach is the most expensive option by a wide margin, produces the most waste, and ironically offers the least guarantee of safety (counterfeit and refilled bottles are documented on popular routes).

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The Best Strategy: Combine Methods

No single purification method is perfect for every situation you will encounter on a Nepal trek. The proven strategy is to combine complementary methods that cover each other's weaknesses.

The Recommended Three-Part System

Primary Method: UV Purifier or Water Filter

Choose based on your trekking style:

• UV purifier (SteriPEN Ultra) if you are tea house trekking on popular routes with charging access. Fast, lightweight, effective against all pathogens.
• Water filter (Sawyer Squeeze) if you are camping, trekking remote routes, or want battery-free reliability. Pair with chemical treatment for virus coverage.

Backup Method: Chemical Tablets (Always Carry)

Pack a minimum of 20 chlorine dioxide tablets (Katadyn Micropur MP1) regardless of your primary method. These weigh 30 grams and serve as your emergency backup if your primary device fails, breaks, runs out of battery, or freezes. Tablets do not fail. They have a shelf life of 5+ years when stored properly. This is your insurance policy.

Supplement: Boiled Water and Safe Water Stations

At tea houses, purchase boiled water for hot drinks (tea, coffee, soups, hot lemon). This supplements your own purification without additional cost beyond what you would spend on beverages anyway. Use Safe Water Stations whenever you encounter them on the EBC or Annapurna routes.

What to Avoid

• Buying plastic bottled water: 600,000+ plastic bottles are discarded on the EBC route annually. The environmental damage is severe, the cost is the highest of any method, and there have been documented cases of bottles being refilled with tap water and resealed
• Relying on a single method with no backup: Electronic devices can fail. Filters can freeze. Bring redundancy
• Drinking untreated water from any source: No stream, tap, or spring in Nepal should be considered safe without treatment
• Using only iodine for treks longer than 3 weeks: Prolonged iodine ingestion affects thyroid function. Switch to chlorine dioxide for extended expeditions

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Environmental Impact: The Plastic Bottle Crisis

The scale of plastic waste generated by bottled water consumption on Nepal's trekking routes constitutes one of the most visible environmental challenges facing the Himalayan ecosystem.

Scale of the Problem

• An estimated 600,000 to 1,000,000 plastic water bottles are brought onto the EBC route annually
• The Annapurna Circuit and ABC routes generate comparable volumes
• Nepal's high-altitude environment means plastic does not degrade for hundreds of years; UV exposure only fragments bottles into microplastics that enter soil and water
• Burning plastic (a common disposal method at remote tea houses) releases dioxins, furans, and other toxic compounds that contaminate air, soil, and water
• Pack animal caravans that carry bottled water up the trail carry additional carbon footprint for a product that is inferior to self-purified water

How Individual Purification Helps

A single trekker using their own purification system eliminates 3 to 5 plastic bottles per day from the waste stream. Over a 14-day trek, that is 42 to 70 bottles. Multiply by the approximately 50,000 trekkers on the EBC route each year, and universal adoption of personal purification would eliminate hundreds of thousands of plastic bottles annually.

Initiatives and Organizations

Several organizations are working to address the plastic bottle crisis:

• Sagarmatha Pollution Control Committee (SPCC): Manages waste collection and cleanup in the Everest region, operates Safe Water Stations, and advocates for bottle-free trekking
• Sagarmatha Next: A comprehensive initiative to make the Everest region plastic-bottle-free through infrastructure development, education, and policy
• Annapurna Conservation Area Project (ACAP): Operates refill stations and promotes waste reduction in the Annapurna region
• Individual tea houses: Many progressive tea house owners now offer boiled water at reasonable prices and discourage bottled water sales

As a trekker, you vote with your wallet. Purchasing a personal purification system is the single most effective action you can take to reduce your environmental footprint on Nepal's trails.

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Water Purification by Trek Route

Different trekking routes in Nepal present different water purification challenges. Here is route-specific guidance.

Everest Base Camp Trek

The EBC route has the best infrastructure for water access of any trek in Nepal. Safe Water Stations are available at most major stops. Tea houses sell boiled water at every village. Charging for UV purifiers is available at Namche Bazaar and several other stops (NPR 300-500 per charge from tea house power outlets or solar stations). A UV purifier with chemical backup is the optimal strategy for EBC.

Annapurna Circuit

The Annapurna Circuit passes through diverse terrain from subtropical lowlands to the 5,416-meter Thorong La pass. Water quality varies considerably. Lower sections have more agricultural contamination; higher sections have glacial silt. ACAP-operated refill stations are available at several points. A water filter works particularly well here because of the variable water clarity, especially in the river valleys where glacial melt produces turbid water that UV cannot treat without pre-filtering.

Remote Treks (Manaslu, Upper Dolpo, Kanchenjunga, Makalu)

Remote routes have no Safe Water Stations, limited tea house infrastructure, and infrequent charging opportunities. A water filter (Sawyer Squeeze or Katadyn BeFree) paired with chlorine dioxide tablets is the best combination. Carry sufficient chemical tablets to treat all your water for the duration of the trek in case the filter fails. A backup power bank for UV purifiers adds significant weight and may not justify itself on routes where weight management is critical.

Camping and Expedition Treks

For treks where you carry your own food and camp rather than staying in tea houses, consider a gravity filter system (Platypus GravityWorks) for base camp use. It can filter water for your entire group while you set up camp. Supplement with individual squeeze filters or UV purifiers during the trekking day.

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Staying Hydrated at Altitude: Beyond Purification

Purifying water is only half the equation. You also need to drink enough of it. Dehydration at altitude is a serious and underappreciated risk that compounds the effects of altitude sickness.

How Much Water You Need

• Below 3,000m: 2-3 liters per day during active trekking
• 3,000-4,500m: 3-4 liters per day minimum
• Above 4,500m: 4-5 liters per day, more during pass crossings or strenuous days
• Acclimatization days: Maintain high fluid intake even when not trekking actively

At altitude, you lose water through increased respiration (breathing harder in dry, thin air), increased urination (the body's response to altitude), and sweat during exertion. The dry mountain air also wicks moisture from your skin and respiratory tract far faster than you notice.

Signs of Dehydration

• Dark yellow or amber-colored urine (aim for pale straw color)
• Headache that worsens with exertion (can mimic altitude sickness)
• Fatigue and irritability beyond what the trekking effort warrants
• Dry mouth and lips despite drinking regularly
• Decreased urine output (you should be urinating every 2-3 hours at altitude)

Hydration Tips

• Start each day with 500ml of warm water before breakfast
• Set hourly drinking reminders; do not wait until you feel thirsty
• Add electrolyte powder to at least one liter per day (ORS sachets are available cheaply throughout Nepal)
• Warm or hot water is absorbed faster and more pleasant to drink in cold conditions
• Avoid excessive caffeine and alcohol, both of which increase dehydration
• Monitor your urine color as the most reliable indicator of hydration status

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Frequently Asked Questions

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Checklist: Water Purification Packing List

Before your trek, make sure you have packed the following. This list complements our complete trekking gear list and Nepal trekking packing list.

Primary Purification (choose one):

• [ ] UV purifier (SteriPEN Ultra or similar) with USB cable
• [ ] OR water filter (Sawyer Squeeze with pouches, or Katadyn BeFree)

Backup Purification (mandatory):

• [ ] Chlorine dioxide tablets (minimum 20 tablets, Katadyn Micropur MP1)

Water Containers:

• [ ] 2x 1-liter wide-mouth water bottles (Nalgene or similar) — wide mouth accommodates SteriPEN and filter attachments
• [ ] 1x insulated bottle or thermos (for boiled water from tea houses)

Accessories:

• [ ] Pre-filter cloth or bandana (for turbid water before UV treatment)
• [ ] Electrolyte powder or ORS sachets (10-14 packets)
• [ ] Backflush syringe (if using Sawyer filter)

Power (if using UV purifier):

• [ ] Power bank (10,000mAh minimum) — see our power banks and electronics guide
• [ ] USB charging cable for purifier

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Final Recommendations

Water purification on a Nepal trek is not a luxury or an afterthought. It is a core safety requirement on par with proper footwear, warm clothing, and altitude medication. The cost of equipment is trivial compared to the cost of a ruined trek or medical evacuation due to waterborne illness.

Invest $40-90 in a quality purification system before your trip. Carry chemical backup tablets that weigh next to nothing. Fill your bottles from Safe Water Stations when available. Buy boiled water for hot drinks at tea houses. And leave every plastic water bottle on the store shelf.

Your stomach, your wallet, and Nepal's mountains will all thank you.