Septic System vs. Public Sewer Home Value Impact, 2022 Report

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When we think about buying a home, our immediate thoughts usually lead to curb appeal, square footage, number of rooms, lot size, and a long list of other wants and needs to meet our individual tastes and lifestyles. We even give thought to structural integrity—like the age and quality of the roof and condition of the foundation—as well as HVAC systems, when thinking about energy efficiency. Another not so fun or exciting, but essential, facet of home ownership is knowing about a home’s private septic or public sewage system.

If your home or the one you want to buy is within city limits, chances are you’re on a public sewer system (not always). On the other hand, homes in more rural areas are usually on septic systems. The reason: it can be costly to run enough pipe to connect a rural property to a city sewage system.

What are some other differences between the two systems, and does one add more value to your home than the other?

Read on. We have the answers.

Do Homes Sell for More with a Septic or Public Sewer?

To answer this question we looked at all the detached homes that sold in Clackamas County and Washington County, Oregon from January 1, 2022 to May 1, 2022 on lots under .46 acres. Why these two counties? These are two of the three counties that make up the greater Portland metro tri-county area, and both have a solid mix of rural and suburban style homes.

Washington County

In Washington County, 12 detached homes sold on less than .46-acre lots on septic systems from January 1 to May 1. These homes sold for an average of $342 per sq. ft. and sold in an average of 12 days on market.

In comparison, 1,756 detached homes in Washington County sold on less than .46-acre lots on public sewer from January 1 to May 1. These homes sold for an average of $313 per sq. ft. and sold in an average of 15 days on the market.

Clackamas County

In Clackamas County 44 detached homes sold on less than .46-acre lots on septic systems from January 1 to May 1. These homes sold for an average of $404 per sq. ft. and averaged 16 days on market.

In comparison, 1,361 detached homes in Clackamas County sold on less than .46-acre lots on public sewer systems from January 1 to May 1. These homes sold for an average of $308 per sq. ft. and took an average of 25 days on market to sell.

Septic vs. Sewer Home ValuePrice per Sq. ft.Days on Market
Washington County Septic$34212
Clackamas County Septic$40416
Septic Averages:$373 per Sq. ft.14 Days to Sell
Washington County Public Sewer$31315
Clackamas County Public Sewer$30825
Public Sewer Averages:$311 per Sq. ft.20 Days to Sell

Homes on Septic Sell for 17% More per Sq. Ft. and Sell 30% Faster than on Public Sewer

If you were thinking that switching to public sewer from your current septic system would increase your home value, think again. Overall, septic systems are cheaper to own and maintain, and certainly, we can see from this report that home buyers have no hesitation in purchasing a home on a septic system within a greater metro area.

What’s the Difference Between a Septic System and a Sewer System?

While there are a few differences between septic systems and sewer systems, the fundamental difference is what happens to waste after you flush. With a septic system, everything is emptied to an underground holding tank in your yard. Solids are separated from the liquids, and the liquids are filtered into the soil. The holding tank is emptied by a professional service three to five times a year. With sewer systems, waste is piped directly to a local water treatment plant for processing.

What are Some Common Septic Systems in Oregon?

There are several types of septic systems, and choosing the best one, depends on factors like soil type, household size, location, and more. Here’s a closer look at how they differ.

Gravity System

Sometimes called a gravity fed system, a gravity system is the more conventional septic system type, comprised of three parts: the tank, the drainfield, and the soil under the drainfield. As you might guess, gravity does all the work, rather than technology, as with a pump.

Solid waste and dark water are sent to the tank where they separate into three layers: scum, effluent, and sludge. The system then extracts the watery effluent layer, which flows to a distribution box for equal distribution to drainfield pipes. The drainfield gets treated by the soil, whereas the scum and sludge layers are treated by natural, good bacteria in the tank. Regular pumping by a qualified technician is required on an as-needed basis, or three to five times a year.

Gravity septic systems can be used in a variety of situations and areas.

Advantages of a Gravity Septic System

  • Easy to service
  • Affordable

Disadvantages of a Gravity Septic System

  • Ground disruptions from vehicles and earthquakes can shift drainfield soil
  • Requires a good slope for gravity to do its job
  • Requires a minimum of 3 feet of soil under the drainfield

Mound System

Mound systems work similarly to conventional drainfields and are sometimes used as an alternative. In this case, sewage is treated with a mound of soil.

With a mound system, the drainfield sits higher than the soil’s natural surface, rather than below, and uses a gravel bed, sand fill, and a series of pressurized pipes. The entire system consists of the mound and replacement area, a tank, and a pump with a dosing pump chamber. With this type of system, after waste enters the tank, it flows to the dosing pump chamber. Floats or timers regulate the pump, and when turned on, wastewater evenly distributes into the pipes then runs through the soil and sand for treatment.

Mound system septics work best in areas with a high water table or shallow soil depth or bedrock.

Advantages of a Mound System

  • Indicates the level of waste water treated before disposing of it from the sand fill
  • Dosing and resting assures even distribution to the drainfield
  • Wastewater travels further before joining groundwater, ensuring a better chance of purification
  • Works in specific soil conditions

Disadvantage of a Mound System

  • Can be hard to install and maintain
  • Must remain free of trees and shrubs
  • Requires a large amount of space
  • Costs more than other systems

Pressure Distribution System

While many situations are suitable for gravity-reliant systems, sometimes installing a system that uses pressure to move wastewater to troughs more evenly is necessary. Components of this type of system are the tank, a dosing pump and pump changer, and a drainfield and replacement area.

This type of system works by wastewater flowing from the tank to the pump chamber, with floats and timers regulating the pump, equally distributing the wastewater. When the water gets to a certain height in the tank, this trips the pump and moves the water, then shuts off so the drainfield can absorb it. These systems also have a high water float to alert you to problems with the system, like too much water in the chamber.

Pressure distribution systems are most suitable for situations when soil depth is limited, the area is aquifer-sensitive, or the drainfield is large or sloped.

Advantages of the Pressure Distribution System

  • Work well in a variety of scenarios and areas
  • Usually have four dosing and resting periods per day
  • Slightly less expensive than gravity systems
  • Less risk of seepage

Disadvantages of the Pressure Distribution System

  • Lines need flushing twice a year to clear residue buildup
  • Requires electricity
  • Can wind up costing more money and time due to maintenance needed

Sand Filter System

The Sand Filter System is considered supreme in the world of septic systems and requires a professional for installation. This type system consists of the tank, pump chamber, sand/gravel filter, and drainfield.

Also known as an intermittent sand filter or a recirculating sand filter, this system works much like a standard septic system. The difference is how the waste water is delivered to the soil. In this case, it filters through a layer of sand and gravel where it undergoes a three-stage process: solids are filtered out, microbes introduce nutrients to the effluent, and contaminants stick to sand grains for organic growth on top of the sand.

The sand filter system is typically used in areas with limited space or insufficient soil.

Advantages of a Sand Filter System

  • Lower material cost to construct and maintain
  • They are energy-efficient
  • Good for areas that are environmentally sensitive or fragile
  • Allow development in problematic sites
  • Create high-quality effluent
  • Can resolve problems with other septic systems

Disadvantages of a Sand Filter System

  • More sensitive to cold, prone to freezing (can sometimes be remedied by adjusting recirculation and dosing)
  • Installed and maintained by professionals, which adds to the cost

What is Cheaper to Own and Maintain, Septic or Public Sewer in Oregon?

Septic System Costs

The homeowner typically owns the full septic system and is responsible for all of its parts. Every few years the septic system will need to be pumped out, depending on the size of the tank and the number of people in the home. Annual checkups are recommended to test electrical and system components to ensure everything is working property. A homeowner can expect to spend roughly $500 a year on their septic system averaged over time. This is typically less than paying government sewer fees plus any maintenance or repairs involving a sewer line.

Public Sewer Costs

Often new home owners think there are no possible costs for the public sewer system. While it is typically true that the local government will care for the sewer line once it crosses out of your lot, any breaks, backups, or sewer line fails on your property can cost the homeowner a lot of money.

If you own or buy an older property with the original sewer lines, know that cast iron was likely used. This type of material has a life span of about 30-50 years, after which point, the lines can start to corrode and rust. Tree roots can break and and bust up the line. Replacement cost can run anywhere between $3,000 to $10,000, depending on how long they are and how deep they’re buried.

The upside to sewer systems is that they require very minimal maintenance and tend to run fine for decades at a time until they need to be replaced or have a problem. They may occasionally require hydro-flushing with water to clear blockages. This service typically doesn’t cost more than a few hundred dollars.

The main ongoing cost for public sewer lines is paying the hefty monthly government fees for the service.

Thinking of Selling your Home in the Future?

We’ve been successfully helping clients in the Portland metro area and beyond for 19 years. We know the ins and outs of real estate transactions and how all facets of a property might impact a sale. We’d love to help you get the price you deserve for your home and make the deal go as smoothly as possible. With our 4% commission and high-level marketing strategy, we’re sure we can. Call our top 1% seller’s team today at 503-714-1111 or chat with the bot on our site. We look forward to talking with you!

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