{"id":2513,"date":"2025-08-20T10:14:50","date_gmt":"2025-08-20T15:14:50","guid":{"rendered":"https:\/\/www.homefieldonsite.com\/east-valley\/?p=2513"},"modified":"2025-08-20T10:14:50","modified_gmt":"2025-08-20T15:14:50","slug":"septic-tank-sizing-per-bedroom","status":"publish","type":"post","link":"https:\/\/www.homefieldonsite.com\/east-valley\/septic-tank-sizing-per-bedroom\/","title":{"rendered":"Septic Tank Sizing Per Bedroom"},"content":{"rendered":"

Determining the correct size for your septic tank is one of the most important parts of designing or replacing a septic system. In both Maricopa and Pinal Counties, septic tank sizing is primarily based on the number of bedrooms in the home. In some cases, the number of plumbing fixtures may be considered as an alternative method.<\/p>\n

Gallons Per Day (GPD) \u2013 What Does It Mean?<\/strong><\/h3>\n

GPD stands for gallons per day<\/strong>, and it refers to how much wastewater your household is estimated to generate. The standard design assumption is 150 gallons per day per bedroom. This number is based on the idea that two people may occupy each bedroom, and each person contributes 75 gallons of wastewater daily.<\/p>\n

Here\u2019s an example:<\/p>\n

4-bedroom home
\n<\/strong>\u00a04 bedrooms x 150 gallons = 600 GPD
\n600 GPD x 2 = 1,200 gallon septic tank<\/p>\n

Your septic tank should be sized at twice<\/strong> your daily flow to provide the right amount of treatment and retention time.<\/p>\n

Minimum Tank Size Rules in Arizona<\/strong><\/h3>\n

Maricopa and Pinal Counties both require that all septic tanks be a minimum of 1,000 gallons<\/strong>, regardless of the number of bedrooms.<\/p>\n

Common Septic Tank Sizes by Bedroom Count<\/strong><\/h3>\n

2 Bedrooms
\n<\/strong>\u00a02 x 150 = 300 GPD
\n300 x 2 = 600 gallon tank
\nBut 1,000 gallons is still the minimum requirement.<\/em><\/p>\n

3 Bedrooms
\n<\/strong>\u00a03 x 150 = 450 GPD
\n450 x 2 = 900 gallon tank
\nAgain, the minimum is 1,000 gallons.<\/em><\/p>\n

4 Bedrooms
\n<\/strong>\u00a04 x 150 = 600 GPD
\n600 x 2 = 1,200 gallon tank<\/p>\n

5 Bedrooms
\n<\/strong>\u00a05 x 150 = 750 GPD
\n750 x 2 = 1,500 gallon tank<\/p>\n

For homes with more than five bedrooms, it\u2019s best to consult with a septic professional to determine the right sizing based on your actual household usage.<\/p>\n

\"Septic<\/p>\n

What Counts as a “Bedroom”?<\/strong><\/h3>\n

When it comes to septic design, a bedroom isn\u2019t just any room with a bed. According to code, a bedroom is any room that:<\/p>\n