What Size Septic Tank For 3 Bedroom House?

Are you considering installing a septic tank but unsure about what size septic tank for 3 bedroom house?

Understanding the ideal septic tank size is crucial for efficient wastewater management as it can save from potential issues like overflows or frequent pump-outs.

In this comprehensive guide, we’ll delve into the determining process for the perfect tank size, explore various types of septic systems, and provide insights into the installation process.

What size septic tank for 3 bedroom house?

For a 3-bedroom house, the recommended size for a septic tank is between 1,000 to 1,500 gallons. This size is based on an estimated daily wastewater flow of up to 360 gallons, accommodating both wastewater and solid waste.

Size Chart for Various House Types:

Number of Bedrooms	Recommended Septic Tank Size (Gallons)	Estimated Daily Wastewater Flow (Gallons)
1-2	750-1,000	240-300
3	1,000	360
4	1,250	480
5 or more	1,500+	600+

Note: Always consult local regulations as they may have specific requirements for septic tank sizes.

Factors to Consider in Choosing the Right Size Septic Tank for a 3-Bedroom House

Household Size

The household size is a big player in the septic tank game. More people in the house means more water being used.

This results in more wastewater that needs to be treated. So, if your family is large, you’ll need a larger tank.

Water Usage

Next up is water usage. If your family loves long showers or does lots of laundry, you’ll need a bigger tank. More water usage means more wastewater to deal with.

Bedroom Count

The number of bedrooms is also important. A 3-bedroom house usually has more people living in it than a 1-bedroom house. More people means more wastewater, so you’ll need a larger septic tank.

Soil Type

The type of soil where you plan to install your septic system can also affect its size and design. Some soils absorb water better than others.

If your soil doesn’t absorb water well, you might need a larger tank or a different type of system.

Regulations and Codes

Don’t forget about local regulations and building codes! These rules often specify minimum septic tank sizes based on the number of bedrooms in your house. Make sure to check these before you start planning your septic system.

Future Expansion

Last but not least, consider any future expansion plans for your house. If you think you might add more bedrooms in the future, it’s smart to install a larger septic tank now. This way, you won’t have to replace it later when your household grows.

Calculating the Ideal Septic Tank Size for a 3-Bedroom House

If you’re building a new house or upgrading your septic system, it’s essential to know the right size of the septic tank you need.

A too-small septic tank can lead to frequent pump-outs and system failures, while a too-large tank can be costly and take up unnecessary space.

Determine the Number of Bedrooms

The first step is to determine the number of bedrooms in your house. This is because the number of bedrooms is used as a basis for calculating the septic tank size.

For a 3-bedroom house, the septic tank size is usually calculated based on a 1,000-gallon tank.

Calculate the Daily Wastewater Flow

The daily wastewater flow is the amount of wastewater that your household produces each day.

To calculate this, you need to know the number of people in your household and the average water usage per person. The formula for calculating the daily wastewater flow is:

Daily Wastewater Flow = Number of People x Average Water Usage per Person

Determine the Required Septic Tank Size

The required septic tank size is calculated by multiplying the daily wastewater flow by the retention time and adding a safety factor.

The retention time is the amount of time that the wastewater stays in the septic tank before it’s discharged into the drain field. For a 3-bedroom house, the retention time is usually 24 hours, and the safety factor is 50%. The formula for calculating the required septic tank size is:

Required Septic Tank Size = Daily Wastewater Flow x Retention Time x Safety Factor

Choose the Right Type of Septic Tank

There are two types of septic tanks: concrete and plastic. Concrete tanks are more durable and have a longer lifespan, but they are also more expensive.

Plastic tanks are cheaper and easier to install, but they are not as durable as concrete tanks.

Install the Septic Tank

Once you have determined the ideal septic tank size and chosen the right type of septic tank, it’s time to install it.

Make sure to follow the manufacturer’s instructions carefully and hire a professional if you’re not comfortable doing it yourself.

Sample Calculation for a 3-Bedroom House

1. Determine the Number of Bedrooms: For our example, we have a 3-bedroom house.
2. Calculate the Daily Wastewater Flow: Let’s assume there are 4 people living in the house and each person uses an average of 100 gallons of water per day. So, the daily wastewater flow would be:
   Daily Wastewater Flow = 4 people x 100 gallons per person per day = 400 gallons per day
3. Determine the Required Septic Tank Size: The retention time is usually 24 hours (or 1 day), and the safety factor is 50% (or 0.5). So, the required septic tank size would be:
   Required Septic Tank Size = 400 gallons per day x 1 day x 1.5 = 600 gallons

So, for a 3-bedroom house with 4 people who each use an average of 100 gallons of water per day, you would need a septic tank that can hold at least 600 gallons.

Types of Septic Tanks for a 3-Bedroom House

Conventional Septic Tanks

Conventional septic tanks are the most common type used in 3-bedroom homes. They work by using natural processes to treat wastewater. Here’s how it works:

1. Wastewater from your house flows into the septic tank.
2. Heavy waste materials sink to the bottom, forming a layer of sludge.
3. Lighter waste materials, like oil and grease, float to the top, creating a layer of scum.
4. The middle layer is liquid wastewater.
5. Bacteria in the tank break down the solid waste.
6. The liquid wastewater then flows out of the tank and into the ground.

Aerobic Treatment Units (ATUs)

Aerobic Treatment Units (ATUs) are another type of septic system. They’re a bit more complex than conventional septic tanks. ATUs use oxygen to break down waste more quickly and efficiently.

This makes them a good choice for larger households or homes with high water usage. Here’s how they work:

1. Wastewater enters the ATU.
2. Air is pumped into the tank to promote the growth of aerobic bacteria.
3. These bacteria break down the waste more quickly than the bacteria in a conventional septic tank.
4. The treated wastewater is then discharged into a drain field.

Maintenance and Care of Septic Tank for a 3-Bedroom House

Regular Inspections

Regular inspections are a must for septic tank maintenance. Have a professional check your system at least once every three years. They’ll look for leaks and check the scum and sludge layers in your tank.

Pumping

Pumping is another important part of septic tank care. Over time, the sludge layer in your tank will build up.

When this layer gets too thick, you’ll need to have your tank pumped out. This usually needs to be done every 3-5 years.

Efficient Water Use

Using water efficiently can help keep your septic system working properly. Try to spread out your water use throughout the week.

This gives your septic system time to treat waste between loads of laundry or dishwasher cycles.

Proper Waste Disposal

Be careful about what you flush down the toilet or pour down the drain. Only human waste and toilet paper should go into your septic system. Avoid flushing things like coffee grounds, grease, or disposable wipes.

Drain Field Maintenance

The drain field is an important part of your septic system. Keep it clear of trees and large plants, as their roots can damage the pipes. Also, avoid driving or parking on your drain field.

FAQs

Conclusion

Choosing the right size septic tank for your 3-bedroom house is crucial. It involves considering several factors, doing some math, and understanding different types of septic systems.

Remember, proper planning and adherence to guidelines can help ensure a functional and trouble-free septic system. Happy planning!