David B. Zilkoski

David B. Zilkoski received a B.S. degree in Forest Engineering from the College of Environmental Science and Forestry at Syracuse University in 1974 and a M.S. degree in geodetic science from The Ohio State University in 1979.  He was employed by National Geodetic Survey (NGS) from 1974 to 2009.   He served as Director, National Geodetic Survey, from October 2005 to January 2009.  During his career with NGS, he established partnerships with state/ local governments and private industry to develop advanced surveying/mapping techniques.  He conducted applied GNSS research to evaluate and develop guidelines for using new technology to generate geospatial products.  As Project Manager of the New Adjustment of the North American Vertical Datum of 1988 (NAVD88) he worked with Federal and State agencies to develop plans to transition from NGVD 29 to NAVD 88.   

Since retiring from government service in 2009, as a geodetic consultant, he provides technical guidance on issues related to NGS’ modernization of the National Spatial Reference System [the replacement of  NAD 83 and NAVD 88 with North American Terrestrial Reference Frame of 2022 (NATRF2022) and North American-Pacific Geopotential Datum of 2022 (NAPGD2022)]; reviews the results of GNSS survey projects; and performs training sessions on guidelines for estimating GNSS-derived coordinates, procedures for performing leveling network adjustments, the use of ArcGIS for analyses of adjustment data/results, and the proper procedures to follow when estimating crustal movement rates using GNSS and geodetic leveling data.  Mr. Zilkoski is Chair of North Carolina Geodetic Survey Advisory Committee, a member of the North Carolina 2022 Reference Frame Working Group, past Chair of the Transportation Research Board (TRB) Committee AFB80 Geospatial Data Acquisition Technologies in Design and Construction, past President of the American Association for Geodetic Surveying (AAGS), a member of the American Geophysical Union, a fellow of AAGS, and currently serves as a GPS World Survey Scene guest editor.

He has authored a number of papers on GNSS-derived heights, subsidence, surveying, and vertical datum including a chapter in The DEM Users Manual (2001, revised 2006 ASPRS, Bethesda, MD, David F. Maune, ed.).  As Guest Editor of GPS World Survey Scene he has authored a series of newsletters on establishing and analyzing GNSS-derived coordinates, understanding NGS hybrid and scientific models, and NAPGD2022 (

NGS Datum 2020

In 2022, to improve the National Spatial Reference System (NSRS), NGS will replace the North American Datum of 1983 (NAD 83) and the North American Vertical Datum of 1988 (NAVD 88) with a new geometric reference frame and geopotential datum.  The new reference frames will rely primarily on Global Navigation Satellite Systems (GNSS), such as the Global Positioning System (GPS), as well as on a gravimetric geoid model.

NAD 83 and NAVD 88 have been identified as having shortcomings that are best addressed through defining new horizontal and vertical datums. Specifically:

  •   NAD 83 is non-geocentric by about 2.2 meters, and
  •   NAVD 88 is both biased (by about one-half meter) and tilted (about a meter coast to coast).

Both datums were defined primarily using terrestrial surveying techniques at passive geodetic survey marks. The survey marks deteriorate over time and resources are not available to maintain them.  These new reference frames will be easier to access and to maintain than NAD 83 and NAVD 88.  It is important that users get prepared for the new datums:

  • Transform Data
  • Tools will be available to transform your data to the new datums from NAVD 88 and the newest realization of NAD 83
  • Record Metadata
  • Knowing the datums and epochs for your geospatial files will simplify your datum transformations
  • Participate in GPS on Bench Marks
  • Obtain precise ellipsoid heights on NAVD 88 bench marks to improve the transformation tool for the new datums.
  • Review State Plane Coordinate System of 2022 (SPCS2022)
  • A procedural document includes contact information and instructions for requesting and proposing zones, as part of developing SPCS2022.
  • Prepare to change legislation, as needed.
  • Currently, 48 states have legislation defining their state-based coordinate system, specifically referring to NAD 83 by name.

We will discuss the history of these datums, their relationship to other reference frames, the reasons for the change, and how it affects surveyors and their access to these datums.  The participant will gain a fundamental understanding of: (1) How and why our datums/reference frames have changed over time, (2) The need to further modernize the US reference frames, (3) How NGS will define new reference frames, and (4) How users will access the new reference frames.



Mark is the Manager of Real Estate Field Services at the Kansas City Southern Railway. In this role, he engages and directs outside survey efforts for the development and maintenance of the 22,000 pieces of real estate that comprise the United States portion of the KCS rail network, directs the UAS program and the GIS rail program. Mark is a Professional Land Surveyor in the State of Missouri, being in private practice for 24 years. During that 24 year span, he was also the elected Lafayette County Surveyor. Mark is a 1981 graduate of the University of Missouri-Columbia and attended two years of law school at MU prior to working for the Railroad. He is the past president of the Missouri Society of Professional Surveyors and an instrument rated pilot.

Surveying the Railroad

Many tracks of land in the Midwest adjoin railroad right-of-way or have been affected by the disappearance of an out of service or abandoned right-of-way. This discussion will talk about all of the things a surveyor needs to consider when establishing a boundary along rail property. Questions are welcome.

  • Safety
  • Permission
  • Survey Approach/Planning
  • Valuation Map/Deed access
  • Deed records and Schedules
  • Occupation and adverse possession
  • Condemnation and Expropriation


Local Road Engineer, Kansas Association of Counties

Norm has spent almost his entire career in county road work and surveying.  He has a bachelors degree in Civil Engineering from Kansas University, and is a Professional Engineer and Registered Land Surveyor.  He was county engineer in Marion, Coffey and Johnson Counties, and retired in 2006.  Since 2007 he has worked part time with the Kansas Association of Counties as Local Road Engineer and teaches classes for the KU Transportation Center.  Norm has been a registered land surveyor since 1973.  He has written 49 articles about surveying for Section Lines the quarterly publication of the Kansas Society of Land Surveyors, and has taught seminars on Rules for Land Surveyors, Surveying Laws, Overlaps & Gaps, Roads & Easements, and History of Surveying in Kansas.

Plat Reviews in Kansas

It has been 8 years since revision of the review laws in 2011.  Prior to 2011 there was a lot of controversy and discord among surveyors concerning reviews.  The 2011 revisions allowed counties flexibility in how reviews were handled, and many unforeseen methods were implemented.  Now is a good time to review the status of reviews in Kansas and discuss what is working and what or where are the problems.  KACS is developing a review best practices guide-what should be in it?  Norm will present the status of reviews in Kansas, and various options that counties have implemented.  There will be a panel of county surveyors talking about issues they have witnessed with time for comments and suggestions from the audience. 


Holmes Murphy, Account Executive/Shareholder

As an account executive and shareholder for Holmes Murphy, Nick Maletta manages and grows the company’s professional liability book of business that consists of services Architects and Engineers.   

Nick Maletta earned his B.A. in Management from the University of Iowa.  Maletta joined Holmes Murphy in 2009 as an intern and has quickly advanced his career within the company, now serving as an Account Executive. Nick continues his professional education with his involvements with the Professional Liability Agents Network (PLAN), and Risk and Insurance Management Society (RIMS) as well as active involvement with AIA and ACEC chapters across the Midwest.  Through dedication to expanding his industry knowledge and identifying strong risk solutions, he builds lasting relationships with his clients and peers.


The liability associated with electronic communication is exposing design professionals in manners never imagined. This is putting pressure on firms and the talent they have to perform at higher levels. One of the challenges this brings is the gap in working styles/communication/processes from senior to millennial staff.

In this session, our partner Holmes Murphy’s Nick Maletta will help you:

  • Refresh & update ourselves on good communication practices
  • Develop an understanding of the nature and liability of poor communication
  • Acquire strategies to respond and manage risk
  • Learn about business practices that mitigate risk

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