Is Septic at KUAO a ‘Constrained Operation’?


The image above is from p.2-30 of the February 2022 draft version of Ch. 1-3 (83p PDF), as shared with the PAC in the current Master Plan process. Orange markings were added by aiREFORM. Note the five green ‘drain fields’ mapped on ODAV lands.

In the same document, at p.2-39, there is text briefly summarizing Sewer/Septic issues. It states, “Sanitary is provided by individual and shared drain field/septic tank systems. There are at least nine individual drain fields located on ODAV owned property that are shared for both aviation related uses on both private and publicly owned land.” This seems to suggest, ODAV lands are being used for drain fields serving structures on private through-the-fence (TTF) properties; it also suggests, at least four drain fields are not yet shown on this Master Plan diagram.

The density of development at KUAO is surprising, especially on these prime agricultural soils. Most of us in this area, if we own acreage and seek to build, one of our biggest front-end problems is to figure out, ‘how do we handle septic wastes’ and ‘will the soils support a sustainable septic drain field’. Sustainable is a key concept; it is NOT sustainable to need to have septic waste pumped out of holding tanks by a weekly service (the present situation, according to multiple people).

The evolution of Aurora Airport has included a huge shift to large hangars and massive impervious surfaces, to accommodate jets larger and heavier than are supposed to use the runway and taxiway. The extent of impervious surfaces developed at the Aurora TTF parcels begs for answers to these questions:

  1. Where precisely are ALL drain fields, how big, and how plumbed to serve which structures (both on and off ODAV lands)?
  2. What are the actual septic demands, and is the current drain field capacity sufficient to meet that demand? If additional drain fields are needed, what sizes, and where will they fit on FAA’s ALP (the critical document, the Airport Layout Plan)? For each plumbed facility, on and off the airport parcel, people should know: how many fixtures, how many projected employees or visitors with how many projected daily uses.
  3. Are these drain fields legal and safe, by Oregon standards? What do the permits say, and do the as-builts conform with the permit designs? How are they positioned reference drainage ditches and surface water features?
  4. Do any septic line locations impact plans for the investment of public funds into runways, taxiways, or other design elements?
  5. Do any drain field locations impact potential new facilities, such as hangars or FBO buildings?
  6. Is FAA OK with drain fields in locations where emergency equipment may need to respond to aviation accidents?

All of these questions – and the answers – need to be fully incorporated into the current Master Plan record. FAA and ODAV need to press this point, to ensure Century West produces the Master Plan content that truly informs everyone, and aids eventual decision-making.