Executive Summary
- Septic tank systems and public sewer lines are distinct methods for handling wastewater, differing significantly in terms of cost, maintenance, and environmental impact.
- Septic tank systems are independent, on-site wastewater solutions that are popular in rural areas. They offer lower monthly costs but come with more installation and maintenance demands than public sewer systems.
- Most medium- and large-sized communities have access to public sewer systems, which are generally more reliable and require less maintenance than septic tanks, albeit at the expense of ongoing utility bills.
- To select the system that best suits your property, consider factors such as your home’s location, usage needs, budget, and long-term plans.
Understanding the Difference Between Septic Tanks and Public Sewer Systems
Although both are wastewater management systems, septic tanks and public sewer systems offer distinct advantages and potential drawbacks for property owners. Comparing septic vs sewer systems and assessing their compatibility with your property is crucial because it can drastically impact your home’s operating costs, compliance with local regulations, and long-term value.
Septic tanks are a popular choice for remote properties because they allow for on-site wastewater treatment. This system consists of a buried tank, a drainfield, and piping that work together to collect, separate, and filter wastewater before distributing it back into the surrounding soil.
However, if your home is in a well-populated area, you likely have access to a public sewer system through a municipal network designed to send wastewater to centralized treatment plants. Although this method is generally more reliable and less demanding than septic tank systems, it comes with its own disadvantages, such as consistent utility bills.
Understanding which system is right for your unique situation requires evaluating costs, infrastructure conduciveness, and environmental considerations. The comprehensive guide below thoroughly compares the pros and cons of septic vs sewer systems.
How Septic Tank Systems Work
Septic tank systems utilize gravity and other natural processes to treat household wastewater on-site, offering homeowners independence through an alternative to public sewer systems, which are more commonly found in densely populated areas.
To understand how a septic tank works and determine if it is a suitable fit for your property, review the following considerations.
Components
Some of the most noteworthy components used in the build of a traditional septic tank system are:
- A buried tank – The heart of the septic tank system holds solid waste, offering an ample enough space for scum to separate from sludge.
- Inlet and outlet baffles – These pipes are used to manage the flow and contain solids.
- A distribution box – This component is essential for evenly distributing effluent to the drainfield.
- A drainfield – This designated area allows effluent to be filtered through the soil, removing pathogens before the water is deposited back into the environment.
Process
After water from sinks, toilets, and appliances enters the septic tank, solids slowly settle, and the remaining effluent is gradually filtered through the drainfield into the soil. This process naturally removes pathogens found in human excrement and other forms of waste.
Maintenance Needs
Keeping up with septic tank services can help you increase the longevity of your system. Some examples of essential aspects of septic tank maintenance are:
- Having a professional pump the tank every 3 to 5 years to remove sludge
- Having the specialist regularly clean filters and inspect the drainfield
- Watching for signs of failure, such as pooling water or foul odors
How Public Sewer Systems Work
Unlike independent septic tanks, public sewer systems are usually maintained by local governments or utility districts. These systems are designed to serve densely populated areas, making them common in large cities and suburban communities.
By reading the following information, you can gain an understanding of how public sewer systems operate and what they require from property owners.
Components
Some crucial elements of sewer systems are:
- House laterals – These are the pipes that connect homes to the main sewer line.
- Main sewer lines – Multiple house laterals converge at main sewer lines, allowing the combined wastewater to be carried to a treatment plant.
- Lift stations – Areas without natural slopes require strategically placed lift stations throughout the length of the sewer line to propel wastewater forward, enabling it to reach the treatment plant.
- Treatment plants – These facilities process and disinfect wastewater before releasing it back into the environment.
Process
When you flush a toilet or let water flow down your sink drain, the wastewater enters the sewer system through a series of underground pipes. After being transported to an off-site facility, the wastewater is treated and then safely and strategically released back into the environment.
Maintenance Needs
Although local governments handle most maintenance services for the shared components of a public sewer system, homeowners still have some maintenance and financial responsibilities, such as:
- Periodic repairs to the sewer lateral line
- Occasional city-mandated sewer inspections
- Monthly utility charges
In general, homeowners are responsible for any issues that occur on their property’s side of the lateral.
At Alpha Environmental, we use the latest methods to provide thorough sewer inspection and repair services.Keep Your Sewer System Functioning with Professional Support
Pros and Cons of Septic Tank Systems
As mentioned earlier, septic tank systems offer independence and lower long-term costs. However, septic tanks require regular cleaning and maintenance, as well as careful site planning.
Review the pros and cons in the table below to understand whether this self-contained wastewater option is right for your property.
| Pros | Cons |
| Lower monthly costs due to the lack of a sewer bill | Installation can be expensive, especially in areas with challenging soils |
| Prevents property owners from being affected by city system outages | Poor maintenance can lead to costly repairs or system failure |
| Septic tank systems may qualify for tax incentives or rebates | Septic tanks are not ideal for large households or multi-unit properties |
Pros and Cons of Public Sewer Systems
Public sewer systems provide convenience and consistent reliability, especially in urban areas. However, ongoing service fees and potential infrastructure issues may affect property owners’ long-term satisfaction and costs with the system.
Read through the pros and cons outlined in the table below to understand how using a public sewer system may affect you.
| Pros | Cons |
| No on‑site tank to maintain or pump | Monthly sewer service charges |
| Consistent performance regardless of soil or weather conditions | The property may be affected by main sewer line issues or capacity overloads |
| Public sewer systems can lead to higher resale values and lender approval rates | May be subject to connection fees and tap installation costs |
Cost Considerations
Several expenses are involved in installing and maintaining waste disposal systems in Portland, Oregon. Some cost-related factors to keep in mind when deciding between septic and sewer systems are:
- Septic installation – Typically, it costs between $10,000 and $25,000 to have a site evaluation performed, a drainfield designed, and a tank installed in the greater Portland area.
- Sewer connection – Although costs vary by city and distance from the main sewer line, sewer connection costs typically range between $3,000 and $8,000, plus tap fees.
- Long-term maintenance – Septic tank pumping typically costs between $300 and $600 every few years. On the other hand, sewer systems require monthly charges that are based on regional demand, which can add up significantly.
Although the costs above are substantial, they are essential for installing and maintaining the health of your septic system or sewer connection.
Regulatory and Environmental Factors
Whether your property is connected to Portland’s public sewer system or relies on a private septic tank, both wastewater management systems are subject to regulations and may impact the local environment.
Septic Systems
In the greater Portland metropolitan area, septic systems are primarily regulated by the Oregon Department of Environmental Quality (DEQ). Some examples of responsibilities that homeowners in Portland may have are:
- Obtaining permits before installing or repairing a septic tank system
- Having the system inspected every 3 to 5 years
- Following strict rules to prevent contamination of local groundwater
If your septic system is maintained correctly, you can reduce the risk of nutrient runoff and help protect Portland’s vulnerable watershed zones, including those that feed into the Willamette River and Johnson Creek.
Sewer Connections
For homes and buildings connected to the public sewer system, the City of Portland’s Bureau of Environmental Services (BES) is responsible for managing wastewater treatment. Some examples of tasks that the BES handles include:
- Enforcing local sewer codes and connection requirements
- Operating large-scale treatment facilities
- Coordinating with the DEQ and federal agencies to maintain water quality
Well-maintained sewer infrastructure ensures that wastewater is consistently collected and treated before it’s discharged back into the environment, reducing pollution and supporting Portland’s city-wide sustainability goals.
Key Factors to Decide Which Is Right
When choosing between septic vs sewer systems, consider the following factors.
- Property location and soil type – Remote or rural properties often lack access to sewer lines, requiring them to utilize one of the various types of septic systems available. Still, soil must pass a percolation test for septic suitability.
- Household size and water usage – Having a lot of occupants can put unnecessary strain on septic tanks. Sewer lines are generally better equipped to accommodate higher flow rates.
- Budget and financing – While septic tank systems have high upfront costs and low monthly bills, sewer systems typically offer the reverse. Nevertheless, some areas provide grants or financing options for certain upgrades.
- Future plans – If you plan to subdivide or develop, you may want to consider relying on sewer systems, as they are easier to expand. Septic tank systems can limit zoning changes or property sales.
Choose the Right Drainage Solution for Your Property
When comparing septic vs sewer systems, it’s essential to weigh both installation and maintenance costs, as well as your household size, the location of your property, soil conditions, and long-term objectives. With numerous factors at play, one wastewater solution may be ideal for one homeland but unsuitable for another, especially when local regulations and environmental impact are considered.
Alpha Environmental Services works hard to ensure your wastewater system meets your needs. Our environmental specialists have substantial experience performing a wide range of services, from septic system design and planning to sewer connection maintenance.
Our team has helped countless homeowners and property developers throughout the greater Portland, Oregon area, ensuring their drainage systems are efficient, code-compliant, and well-maintained. With our extensive industry knowledge and dedication to supporting our fellow Oregonians, we have helped extend the lifespan of septic tanks and sewer systems throughout the northwestern part of Oregon. Schedule a consultation with Alpha Environmental today to facilitate informed decision-making about your property’s wastewater management.
