landfill airspace

November 20, 2019

Welcome to the SCS Advice from the Field blog series.

landfill airspace

Airspace is a golden egg, the equivalent to cash that a waste operating company will have overtime in its account. With each ton or cubic yard of waste received at the landfill, the non-monetary asset of airspace converts positively to the bottom line of the waste operating company’s books.

The larger the airspace, the larger the non-monetary asset, and the larger future cash potential in the account.

Therefore, it is extremely important to design landfill footprints optimally in consideration of planned operations at the site, and design landfill features maximizing airspace within the selected landfill footprint.

Optimization takes into consideration the land available for development, including the various facilities and systems necessary for operations. The type of design, depth of landfill, base slopes, leachate collection pipe slope, perimeter berm geometry and size, slopes of landfill side slopes, terraces on slopes, and many other parameters determine the airspace volume available to the landfill operator. The designer’s goal is to provide the most volume to the landfill operator.

How does the operator know that a proposed design is maximizing airspace?

If SCS is the site designer, the maximization of airspace is inherent in proposed designs for permitting. On numerous occasions, when SCS is not the site engineer, our designers have proposed a re-design of landfill features to maximize the airspace within its permitted footprint. Under these circumstances, it is not easy to convince a landfill operator of the benefits of SCS’s proposal. Naturally, one assumes a designer would not propose a lesser design on paper and carry it through the high cost of permitting, so it is common for the landfill operator to express doubts about our proposed changes. Once the operator and SCS review the technical design changes in detail, the demonstrated value becomes apparent. It is not a simple process, but on every occasion, we have successfully increased the airspace for the client, increasing potential revenue for millions of dollars beyond the originally permitted amounts.

Driven by the success of our clients, it is our culture to serve our clients completely as trusted professionals making your challenges our own. SCS is proud to say that at the date of this publication, our designers have created over $400,000,000 of additional financial benefit out of thin air for clients at a dozen landfills with more efficient landfill base grades that maximize airspace and cost less to construct.

As we move toward our 50th year, we hope to continually improve, evolve, and strive to maximize airspace at more landfills, adding value to our clients’ bottom line. Contact our nearest office if you are interested in a landfill evaluation for maximizing airspace and reducing construction costs. As always, our SCS authors are available to answer your questions or comments.

Landfill Design


Ali KhatamiAbout the Author:  Ali Khatami, Ph.D., PE, LEP, CGC, is a Project Director and a Vice President of SCS Engineers. He is also our National Expert for Landfill Design and Construction Quality Assurance. He has nearly 40 years of research and professional experience in mechanical, structural, and civil engineering.






Posted by Diane Samuels at 6:00 am

July 30, 2018

Landfill base grades not only make leachate collection and removal possible but also have a significant impact on the amount of landfill airspace. For landfill operators, airspace is the primary asset, because it represents the level of revenue the operator can expect. Airspace is a commodity to be maximized.

Operators expect to get the most airspace from their landfill designer and depend on the engineer to design the grades to maximize it. Placing your trust in an engineer is a noble matter, but as the operator, you check, verify, and confirm that what the designer has engineered is what is needed to provide you with the expected value. An experienced landfill designer looks for ways to provide airspace above and beyond the operator’s expectations.

SCS has been in the business of designing landfills for nearly half a century. We have significant experience in optimizing landfill designs and maximizing airspace. SCS is often retained to design a new expansion to an existing landfill. Upon starting work we analyze the entire facility holistically to see all of the potential ways to maximize airspace around and above the existing landfill. Every cubic yard of additional airspace is a big achievement for our clients and in turn for us.

SCS often evaluates permitted, yet to be developed, base grades for operators. The intent is to determine whether additional airspace can be achieved by applying a different design to the base of the landfill. SCS has turned the science of geometry into mathematical models utilized to quickly evaluate base grades. Specific parameters of the currently permitted base grades are plugged in the mathematical model along with those of the alternative and the model provides quantitative values (cubic yards) of the difference between the permitted grades and the alternative. The values are quickly returned. After modeling, the operator may decide to modify the design to gain the additional airspace based on the alternative design. Contact us to work with our landfill design experts to assist you with an evaluation.

Contact Dr. Ali Khatami with questions about the model.




Posted by Diane Samuels at 11:12 am