It’s Not Your Father’s Septic Tank Anymore! (Part 2 of 3)

ASTM C-1227 Standard Changes the Way Concrete Precasters Make Septic Tanks

Precasters Failing to Recognize the Importance of the Shift in Attitude Toward Septic Tanks Are Likely to Find Themselves on the Endangered Species List

Exerpt from C-1227, Standard Specification for Precast Concrete Septic Tanks


Section 6.1. Structural design of septic tanks shall be by calculation or by performance.

Section 6.1.1 Design by calculation shall be completed using the Strength Design Method (ultimate strength theory) or the Alternate Design Method (working stress theory) outlined in ACI 318-89.

Section 6.1.2. Design by performance requires the manufacturer to demonstrate that failure will not occur by physically applying loads to the product. The load applied shall 1.5 times the anticipated actual loads.

Section 6.1.3. Tanks shall be designed so that they will not collapse or rupture when subjected to anticipated earth and hydrostatic pressures when the tanks are either full or empty.

ASTM Committee C27 meets once a year, in December. The Committee, with a membership of approximately 150 members, has jurisdiction of 24 standards. C27 has 6 technical subcommittees. These standards play an important role in the design and specification of precast concrete products. C27 standards are published in Volume 04.05 of the Annual Book of ASTM Standards. Annual membership dues are $75.00 for individuals.

Visit if you want to learn more about becoming involved in ASTM

Critics of ASTM C-1227 have been heard making the statement that the standard is “not worth the paper that it is written on”. These critics make the erroneous argument that it lacks proper engineering principles for the design of structurally sound tanks. Similarly, critics argue that the standard lacks adequate methods of performance testing, such as testing for watertightness.

Figure 2. Vacuum Testing Precast Tanks Per C-1227 Requirements. Testing performed at the 2005 NOWRA Annual Convention, Cleveland, OH

ASTM standards are known as consensus standards. This means that a standard only becomes recognized after it has gone through a thorough vetting process where the input of all interested parties has been reviewed and subject to membership acceptance. Membership in ASTM is open to all individuals with an interest in developing advancements in the precast concrete industry. ASTM Committee C-27 welcomes the participation of health regulators, specifying engineers and other industry interested persons. Unfortunately, most of the critics of C-1227 criticize from afar rather than understand and participate in the process. Unbelievably, some critics have never even read the standard, yet they repeat the critical comments of other equally ill-informed individuals. This repeating of unsubstantiated misinformation is best described as the “Chicken Little – The Sky is Falling” phenomenon.

National Small Flows Clearinghouse

Beginning in the 1970s, the U.S. EPA became more active in funding programs promoting education and technological advancements in the onsite wastewater industry. One example of this programming is the National Small Flows Clearinghouse (NSFC). Established in 1977, NSFC provides technical assistance and information services about “small flows” wastewater treatment systems. A “small flows” system is one that has one million gallons or less of wastewater flowing through it each day, ranging from septic systems to small sewage treatment plants. Industry studies conducted through the NSFC initiative have had a great deal of influence on the development of many of the new onsite regulations. Individuals seeking additional information on NSFC, including past copies of the Small Flows Quarterly magazine published by NSFC, should visit their website at

National Onsite Wastewater Recycling Association

Founded in 1991, the National Onsite Wastewater Recycling Association (NOWRA), brings tank installers, waste haulers, academia, health officials, manufacturers and federal agencies together to advance the state of the onsite industry. NOWRA’s mission is “to provide leadership and promote the onsite wastewater treatment and recycling industry through education, training, communication and quality tools to support excellence in performance”. NOWRA is currently in the final stages of developing a “Model Code” which could very well serve as the blueprint for new state and local onsite septic regulations. Many states have formed affiliate onsite wastewater associations. Precasters need to be involved in these associations which have far reaching influence on the development of regulations, system specifications, and industry practices. (Learn more about NOWRA and state affiliate associations at

To summarize, precasters failing to become involved in local, state or national onsite wastewater associations are headed toward the endangered species list.

Read on for more information about EPA guidelines and how they refine our industry.


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