ANTHC awarded two U.S. patents for rural sanitation and infrastructure projects

February 13, 2023

From its inception, ANTHC has been dedicated to improving the health and quality of life of Alaska Native people. Meeting the unique public health challenges of rural Alaska’s communities takes more than dedication and perseverance. Sometimes it takes ingenuity. 

John Warren, a civil engineer and director of Standards and Innovation at ANTHC, knows the public health, safety and climate issues concerning rural communities. He works with ANTHC Environmental Health and Engineering engineers and public health specialists who turn ideas into reality that change the lives of Alaskans. Finding solutions that are simple, inexpensive and transformational are what drive Warren to think outside the box.  

“Our customers are our concern,” Warren said about developing solutions that are easy to operate and require little maintenance. 

Warren and a dedicated team of engineers recently had two of their projects awarded U.S. patents on behalf of ANTHC. 

Portable Alternative Sanitation System (PASS)

For some Alaska communities that are vulnerable to flooding and erosion, piped sanitation infrastructure isn’t physically, or financially, feasible. For these areas, ANTHC engineers have designed a low-cost sanitation alternative that addresses the most basic needs of hand-washing, safe drinking water, safe human waste handling and improved indoor air quality. The system takes very little space, is simple to operate and can be disassembled and reassembled in a new location, as needed.

The Portable Alternative Sanitation System, also known as PASS, was awarded a U.S. patent in November 2021. It consists of a water treatment system, gravity-fed water storage tank, low-flow sink, waterless urinal, separating dry toilet, ventilation fan, seepage pit and optional rain catchment system. And since PASS is a portable, stand-alone system, it can be moved along with a household.

The PASS and its simplified version, the Mini PASS, are currently in more than 470 homes that would otherwise be using a honeybucket and water hauled in open tanks that is subject to contamination. Having in-home water and sanitation makes healthy hygiene practices easier, which has been shown to reduce illness according to public health research, including reports from ANTHC studies. Ongoing evaluations of households with PASS and Mini PASS units show these systems have made a difference both in the quality of life and in better health for families.

Hybrid Thermosiphon System

Arctic communities are especially vulnerable to climate change, and protecting critical infrastructure built on permafrost means keeping the ground frozen beneath them. Thermosiphons are used to stabilize permafrost under buildings, roads, and pipelines by chilling the ground. These fluid-filled, vacuum-sealed tubes operate when the ground temperature is warmer than the ambient air temperature. As the ground warms, the fluid in the bottom of the tube vaporizes (consuming heat) and rises to the top of the tube where the gas condenses due to cold air temperatures. The cycle repeats as the fluid returns below ground. This passive process occurs when there is sufficiently cold air temperatures to cause the gas to condense to a liquid. 

Rising winter air temperatures and longer summers are reducing the effectiveness of these passive cooling systems. This is where Warren and ANTHC engineers William Fraser and Bailey Gamble put their talent to work. They designed a mechanical chiller that clamps onto the existing thermosiphons. This extends the cooling capacity of the thermosiphons beyond the cold season and creates the year-round ability to keep the ground frozen. These cooling collars can be powered with solar energy, offsetting the cost of running the thermosiphons in summer months. 

“I love elegant engineering solutions,” said Warren. “Why not take the abundant summer sun that is thawing the ground and put it to work freezing the ground? Work with Mother Nature. Keep it simple and take what works against you and make it work for you.”

A U.S. patent was awarded to ANTHC, Warren, Fraser, and Gamble in August 2022 for the Hybrid Thermosiphon System for its innovative approach to preserving at-risk infrastructure in cold climates. 

While patents are the official proof of ingenuity, it’s the reason behind them that inspires Warren. He’s been working on solutions for rural Alaskans at ANTHC for over 21 years. 

“The opportunity to help people is why I come to work,” Warren said.

Patents protect ideas. They give credit to the creative minds that develop a new concept into something useful. ANTHC’s patents not only document its contribution to better living in Alaska’s challenging climate and geography, they are a testament to the dedicated staff who work on behalf of rural Alaska’s communities and public health. 

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