CLEAN WATER SUPPLY AND ON-SITE SEPTIC WASTEWATER TREATMENT SYSTEMS AT OXALIS ADVENTURE CAMPSITES

On multi-day expeditions through Phong Nha - Ke Bang National Park, Tu Lan, Hang Ba, and Hang Tien, camping in the wilderness is often one of the most memorable parts of the journey. But these remote areas have no permanent infrastructure. This makes providing clean water and treating wastewater a challenge. How can we provide basic comfort for our guests while protecting groundwater and the surrounding forest ecosystem?

With a strong commitment to environmental protection, Oxalis Adventure continues to improve our operations and find better ways to enhance the guest experience. After extensive research, we introduced two pioneering technical solutions at our campsites: a Domestic Clean Water Supply System and an Above-Ground Septic & Wastewater Treatment System. These systems help protect the surrounding environment while keeping our campsites comfortable and hygienic for our guests.

1. Domestic Clean Water and Drinking Water Supply System

In the remote forest environment, ensuring a reliable supply of clean water and safe drinking water for our guests is a top priority of Oxalis. The campsite water supply system follows a simple three-step process:

• Step 1 - Source water pumping: Water is pumped from natural streams into elevated storage tanks placed in dry areas. The pumps are powered by solar energy or environmentally friendly portable generators.
• Step 2 - Multi-stage filtration: Water from the initial storage tanks passes through multi-stage filters containing natural materials such as sand, gravel, and activated carbon. These filters remove sediment, dirt and other impurities. They also help reduce natural odors in the stream water. Chlorine is then used to disinfect the water and remove E. coli and Coliform bacteria before being used for daily activities.
• Step 3 - Domestic water supply & boiled drinking water: After filtration, the water flows into storage tanks and is distributed to the campsite's main facilities, including toilets, wash areas, showers, and the kitchen. All drinking water for guests and staff is boiled thoroughly before use. This helps ensure safe drinking water and protects guests' health.

Handwashing area at the campsite.

2. Above-Ground Septic & Wastewater Treatment System

Previously, waste at Oxalis campsites was managed by using rice husks to support composting. Porters then carried the compost out of the caves. Today, with advances in technology and the need for a more effective solution, Oxalis has invested in a new septic toilet and wastewater treatment system. The system follows a controlled treatment process that meets environmental standards:

• A. Toilet: Toilets are set up in private tents. They use ceramic toilet bowls mounted on portable bases, providing a familiar level of comfort similar to that of a hotel. A closed piping system carries all waste to a central treatment tank. The human waste treatment system utilizes three 500-liter above-ground septic tanks connected in series (one to the next) to process all toilet waste systematically.
• B. Microbial Treatment: Primary & Secondary Digestion. The three connected tanks are regularly treated with specialized microbial products. Beneficial bacteria actively break down organic solid matter across the multi-tank system, significantly reducing unpleasant odors and prepping the effluent for post-treatment.
• C. Filtration Tank: Polishing Stage. After moving sequentially through the three-chamber septic setup, the liquid waste passes through a dedicated Filtration Tank to remove remaining suspended solids and particulate matter.
• D. Chlorination Container: Disinfection. The filtered water flows into a final holding container treated with Chlorine (Clo) to neutralize pathogens and disinfect the water thoroughly.By implementing this multi-stage system - combining primary biological digestion, filtration, and final chlorine disinfection - all waste from the toilets is properly treated, sanitized, and safe for environmental discharge.
• E. Safe discharge & testing every 3 months: Only after the treated water has passed the disinfection stage and meets the required standards is it discharged into the natural environment. To ensure long-term environmental safety, Oxalis collects and tests wastewater samples every 3 months through independent testing facilities.

The campsite provides clean, modern and well-equipped restroom facilities.

Wastewater treatment system.

3. Conservation and Enhanced Guest Experience Significance

The combination of the Domestic Clean Water Supply System and Above-Ground Septic & Wastewater Treatment System brings several practical benefits:

• Protecting the ecosystem and groundwater: No burial pits are needed, and no untreated waste is discharged into caves or streams. This helps preserve the pristine environment of Phong Nha - Ke Bang National Park.
• Improving guest comfort and peace of mind: Guests can enjoy clean and private toilet facilities, an odor-free environment, and safe water for washing and drinking after boiling, even deep in the forest.
• Reducing the workload for porters: The above-ground septic tank means porters no longer need to carry waste out of the forest as they did under previous systems. They can instead focus their energy on caring for guests and ensuring a better expedition experience.

These initiatives demonstrate Oxalis Adventure’s ongoing commitment to improving operational standards and promoting sustainable tourism across all of our expedition journeys.