Septic 101: Advanced Septic Systems

Advanced septic systems, or as Oregon refers to them- an ATT (Alternative Treatment Technologies), are the newest advancement in the septic industry that provide an additional level of treatment, like a filter or additional . These modern systems give homeowners piece of mind by providing great alternatives to a gravity based septic system in places where treatment would otherwise be difficult due to insufficient land, poor soil, high groundwater, or proximity to a large body of water. In fact, alternative treatments many times produce cleaner effluent than any gravity based septic system.

In this article we will cover the basics of how ATTs differ from a traditional gravity system and how they must be maintained. There are too many ATT systems to cover in one article but we will share information relating to ATTs in Oregon and Washington’s Klickitat county, the county we are licensed to work in, and provide some advice on where to learn more about systems that will work well for your home.

The Oregon Department of Environmental Quality classifies ATTs as “devices that can be connected to a standard septic system and are designed to provide an additional treatment in order to protect your health and the environment”. Under the Oregon DEQ, a septic system for a property is determined by the DEQ through a site evaluation they perform. If the DEQ inspector recommends an ATT, they will recommend one of two levels, Treatment Standard 1 and Treatment Standard 2. Additionally, these ATTs will require a yearly maintenance contract from a certified maintenance provider. The DEQ has list of certified maintenance providers on their website, of which we are included.

Treatment Standard 1 is a system that requires greater separation if wastewater because the wastewater is higher in bacteria. The systems are the most commonly recommended systems and can range in price from $15,000 to $40,000. While this price is high, it is in most cases cheaper than hooking up to city sewer. These systems will have multiple treatment units and advanced filters that must be cleaned regularly. Most commonly, these units are recommended in Oregon when a drainfield or whole system has failed from lack of regular maintenance. (Remember to pump and inspect regularly!)

Treatment Standard 2 is a system that disinfects and has the ability to reduce nitrogen. These systems includes sand filters, which are just as they sound- a layer, mostly above ground, of sand that wastewater passes through for an additional filtration process. These systems are not seen as frequently in DEQ site evaluation recommendations, but they also require a yearly maintenance contract from a certified maintenance provider.

While there are two categories for ATTs, we have systems that will fit into both categories. We have a wide range of ATT options that can work with any wastewater situation and budget. There have been incredible advancements in onsite wastewater systems, like a “living” filters that can clean your water back to drinking condition before it enters back into the groundwater.

Washington state’s rules are similar to Oregon’s but do vary per county. The WA Department of Health (DOH) is the government body that oversees septic systems. They require, like the DEQ, a site evaluation for a new system along with test pits. Once an agent of the county has been out to assess the property, they recommend a system type. Though they are less stringent than Oregon, they do dictate if a standard system is needed or a certain type of ATT (called an ATU or Alternative Treatment Unit in Oregon). The DOH has a list of accepted ATUs installers can use based off the recommendation from the county agent.

ATTs or ATUs do not take much more time to install than a regular septic system, which is about 3 business days, but can require a greater waiting period for a specific tank, filter, or part. Make sure when you choose your installer they can secure all the working parts to your system to make your installation timely.