Septic System Frequently Asked Questions

At Septic Response, we believe homeowners should understand how their septic system operates and what it takes to keep it functioning properly. Below are answers to some of the most common questions we receive about septic pumping, maintenance, inspections and system care.

What should I avoid putting into my septic system?

Your septic system is designed primarily to treat wastewater and biodegradable waste. Avoid flushing or draining materials that do not break down easily or that may interfere with the treatment process.

Items that should be kept out of your septic system include:

• Baby wipes and so-called “flushable” wipes

• Feminine hygiene products

• Paper towels and cleaning wipes

• Diapers

• Grease and cooking oils

• Food 

• Coffee grounds

• Paint, solvents and harsh chemicals

• Medications

Even products marketed as flushable may not break down quickly enough for a septic system. As a general rule, toilets should be used for human waste and toilet paper—not as a household disposal system.

Should I know where my septic tank and drainfield are located?

Yes. Every septic system owner should know the approximate location of the septic tank, access lids, pump chamber, drainfield and other major system components.

Knowing where these components are located makes inspections and maintenance easier and can help prevent accidental damage from construction, landscaping, excavation or vehicles.

If you do not know where your system is located, Septic Response can assist with locating accessible system components. Septic system records or as-built drawings may also be available through the local health jurisdiction.

Is it okay to use a garbage disposal with a septic system?

Garbage disposals can be used with some septic systems, but minimizing their use is generally better for the system.

Food waste entering the septic tank increases the amount of solids that must be retained and eventually pumped from the tank. Heavy garbage disposal use can therefore contribute to faster sludge accumulation and may increase how frequently the tank needs to be pumped.

Whenever possible, dispose of food waste in the garbage or compost rather than sending it into the septic system.

My septic tank is buried. Is there a better way to access it?

Yes. Septic tank risers can be installed to bring buried access openings closer to or up to finished grade.

Properly installed risers provide easier access for future pumping, inspections and maintenance and can eliminate repeated excavation of the same access points.

Risers should be securely attached and properly sealed to help prevent groundwater, surface water and soil from entering the tank. The lids should also be securely fastened to prevent unauthorized or accidental access.

Septic Response can evaluate existing tank access and install appropriate risers and secure lids when needed.

How often should I pump my septic tank?

There is no single pumping interval that is correct for every septic system.

Many residential septic tanks are pumped approximately every three to five years, but the appropriate interval depends on factors such as:

• Tank size

• Number of occupants

• Wastewater usage

• Sludge and scum accumulation

• Garbage disposal use

• System design

• Previous maintenance history

The best approach is to inspect the tank and evaluate the actual sludge and scum accumulation rather than relying exclusively on a calendar.

Allowing solids to accumulate excessively increases the risk of solids reaching downstream components and potentially affecting the drainfield. Routine inspection allows pumping to be performed when the system actually needs it.

How often should my septic effluent filter be cleaned?

If your septic system has an effluent filter, it should be inspected and cleaned regularly.

The appropriate frequency depends on the system design, wastewater usage and how quickly solids accumulate. For many residential systems, inspecting the filter during routine septic maintenance is appropriate, with cleaning performed whenever buildup begins restricting flow.

A clogged effluent filter can restrict wastewater leaving the tank and, in severe cases, contribute to high liquid levels or plumbing backups.

The filter performs an important function by helping prevent larger suspended solids from traveling downstream toward the drainfield.

Can I do all of my laundry on the same day?

Spreading laundry throughout the week is generally better for a septic system than completing numerous loads consecutively.

Every load introduces a substantial amount of wastewater into the system. Multiple back-to-back loads—combined with showers, toilets, dishwashers and normal household water use—can create a large hydraulic load over a relatively short period.

Spacing laundry loads gives the septic system and drainfield more time to receive and distribute wastewater.

Modern high-efficiency washing machines can also reduce the amount of wastewater entering the system.

What are the warning signs of a septic system problem?

Common warning signs include:

• Slow-draining sinks, tubs or showers

• Toilets that flush slowly

• Gurgling plumbing

• Sewage backing up into the home

• Septic alarms

• Sewage odors around the tank or drainfield

• Unusually wet or saturated areas near the drainfield

• Surfacing wastewater

• Abnormally green or lush vegetation over portions of the drainfield

These symptoms do not automatically mean that the drainfield has failed. Pump failures, clogged filters, damaged piping, control problems, excessive water use and other conditions can produce similar symptoms.

The system should be properly diagnosed before determining what repair is necessary.

What should I do if my septic alarm goes off?

Reduce unnecessary water use and have the system evaluated.

A septic alarm commonly indicates that the liquid level in a pump chamber or treatment component has moved outside its normal operating range. Possible causes include a failed pump, float problem, electrical/control issue, restricted discharge line, excessive water entering the system or a downstream problem.

An alarm does not automatically mean that the pump has failed or that the drainfield needs replacement. Proper testing should be performed to determine the actual cause.

Avoid repeatedly silencing an alarm without addressing the underlying condition.

Does pumping my septic tank fix a failing drainfield?

Not necessarily.

Pumping removes accumulated sludge, scum and wastewater from the septic tank, but it does not correct the underlying cause of most drainfield problems.

Drainfield performance problems may involve hydraulic overloading, excessive biomat accumulation, damaged piping, root intrusion, poor distribution, clogged pressure laterals, loss of system pressure, saturated soil or other conditions.

A properly diagnosed drainfield problem may require cleaning, hydro-jetting, distribution repairs, pump or control repairs, resting portions of the field, or more extensive corrective work depending on the system and the cause of the problem.

What is the difference between septic pumping and a septic inspection?

Septic pumping and septic inspections serve different purposes.

Septic pumping removes accumulated solids and wastewater from the tank.

A septic inspection evaluates the condition and operation of the system and its accessible components. Depending on the system type, an inspection may include evaluating tanks, baffles, filters, pumps, floats, controls, liquid levels, distribution components and the drainfield area.

Pumping a septic tank should not automatically be considered a substitute for a complete septic system inspection.

How often should my septic system be inspected?

Inspection requirements depend on the type of septic system and applicable local regulations.

In Washington, gravity systems generally require inspection at least once every three years, while many non-gravity systems require more frequent inspection. Certain proprietary or advanced treatment systems may also have manufacturer-specific or local maintenance requirements.

More frequent evaluation may be appropriate when a system has pumps, treatment components, a history of problems or other conditions requiring closer monitoring.

Septic Response can help identify the type of system you have and the appropriate maintenance requirements for that system.

What does a septic pump do?

In systems that cannot rely entirely on gravity, a septic pump moves effluent from a pump chamber to another treatment or dispersal component, such as a pressure distribution drainfield, sand filter or advanced treatment system.

The pump works together with floats, controls, piping and other components to deliver wastewater at the intended operating level or dose.

When diagnosing a pump system, it is important to evaluate more than whether the pump simply turns on. Pump performance, flow, pressure, floats, controls, discharge piping and downstream conditions may all affect system operation.

What are septic floats?

Floats are control devices located inside many septic pump chambers. They respond to changing liquid levels and can control functions such as turning a pump on, turning it off or activating a high-water alarm.

Depending on the system design, multiple floats may be used for pumping, alarms, redundant-off protection or timed-dose controls.

Correct float positioning and operation are important because improper settings can affect dose volume, pump cycling and overall system performance.

What is a pressure distribution drainfield?

A pressure distribution system uses a pump to deliver effluent under pressure through a network of small-diameter pipes and calibrated openings called orifices.

The objective is to distribute wastewater more evenly across the available drainfield area than would typically occur with simple gravity distribution.

Proper operation depends on adequate pump performance, pressure, clean laterals and orifices, functioning controls and appropriate dosing.

Loss of pressure or uneven distribution should be diagnosed before assuming that the drainfield itself has failed.

Can septic drainfield laterals be cleaned?

In certain systems, particularly pressure distribution systems, accessible laterals may be flushed or hydro-jetted to remove accumulated material and help restore proper flow through the piping and orifices.

Whether this service is appropriate depends on the system design and the cause of the performance problem.

Hydro-jetting is not a universal cure for a failed drainfield. The system should first be evaluated to determine whether the problem involves the laterals, pump performance, distribution system, hydraulic loading, soil absorption area or another component.

What is a septic baffle, and why is it important?

Septic tanks typically have inlet and outlet baffles or tees that help control wastewater movement through the tank.

The inlet baffle helps direct incoming wastewater into the tank, while the outlet baffle helps prevent floating scum and suspended solids from traveling into downstream components.

Damaged, deteriorated, missing or improperly positioned baffles can interfere with normal tank operation and potentially allow solids to move toward the drainfield.

Baffles should therefore be evaluated during appropriate tank inspections and repaired or replaced when necessary.

Should septic tank lids be brought to grade?

Bringing appropriate access openings to grade with properly installed risers can make routine inspection, pumping and maintenance significantly easier.

Surface-accessible lids eliminate repeated excavation and make it easier for technicians to inspect important components.

However, lids and risers must be structurally appropriate, securely installed and properly sealed. Access lids should remain secured to reduce the risk of accidental entry.

Can vehicles drive over my septic tank or drainfield?

Generally, no.

Vehicles, heavy equipment and other concentrated loads can damage tanks, piping and drainfield components and may compact the soil used for wastewater treatment and dispersal.

Unless a particular component has been specifically engineered and approved for traffic loading, keep vehicles and heavy equipment away from septic tanks, pump chambers and drainfields.

How long does a septic system last?

There is no universal lifespan for a septic system.

System longevity depends on the original design and installation, soil conditions, wastewater loading, system type, maintenance history, water usage and whether components have been damaged or neglected.

Some components, such as pumps, floats and controls, may require replacement during the overall life of the system.

Routine inspections and appropriate maintenance can identify developing problems early and help protect the system’s long-term performance.

Should I use septic additives?

Routine use of septic additives is generally not necessary for a properly functioning residential septic system.

Normal household wastewater already introduces microorganisms into the septic tank. Additives should not be viewed as a substitute for proper system operation, inspections, pumping or necessary repairs.

If a product claims that it eliminates the need to pump a septic tank, homeowners should be particularly cautious. Accumulated inorganic and organic solids still need to be evaluated and removed when appropriate.

Can heavy water use damage my septic system?

Excessive hydraulic loading can contribute to septic system problems.

Large volumes of wastewater entering the system over a short period reduce settling time in the tank and place additional hydraulic demand on the drainfield.

Repair leaking toilets and fixtures, spread high-water-use activities throughout the week and avoid unnecessary water use when the system is already experiencing problems.

Do I need to pump my septic tank before an inspection?

Not always.

Pumping and inspection are separate services, and pumping immediately before certain evaluations can remove liquid levels or operating conditions that may otherwise provide useful diagnostic information.

Whether pumping is necessary depends on the purpose of the inspection, solids accumulation, system condition and applicable local requirements.

When possible, determine the inspection requirements before automatically pumping the system.

What should I do if I see standing water near my septic tank or drainfield?

Avoid contact with the water and reduce unnecessary household water use until the cause can be evaluated.

Wet or saturated areas can result from several conditions, including leaking tank or piping components, groundwater infiltration, hydraulic overloading, pump problems, damaged distribution components or a malfunctioning drainfield.

Surfacing wastewater should be treated as a potentially serious condition. A septic professional should determine the source before repairs are recommended.

Why is preventative septic maintenance important?

A septic system is a wastewater treatment and dispersal system, not simply a storage tank.

Routine maintenance can identify excessive solids accumulation, clogged filters, deteriorating baffles, pump problems, float issues, leaks and distribution problems before they develop into larger failures.

Preventative maintenance also provides homeowners with a better understanding of the condition of their system so repairs can be based on actual findings rather than assumptions.

Need Help With Your Septic System?

Septic Response provides professional septic pumping, inspections, diagnostics, maintenance and repair services throughout our Western Washington service area.

Whether you need routine maintenance or are experiencing an alarm, backup, pump problem or drainfield concern, our technicians can evaluate the system, identify the likely cause and recommend the appropriate next step.

Contact Septic Response at (206) 962-2600 to schedule septic service.