[Federal Register Volume 85, Number 193 (Monday, October 5, 2020)]
[Notices]
[Pages 62698-62708]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-21902]


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DEPARTMENT OF COMMERCE

National Institute of Standards and Technology

National Oceanic and Atmospheric Administration


Deprecation of the United States (U.S.) Survey Foot

AGENCY: The National Institute of Standards and Technology and National 
Geodetic Survey (NGS), National Ocean Service (NOS), National Oceanic 
and Atmospheric Administration (NOAA), Department of Commerce (DOC).

ACTION: Notice; final determination.

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[[Page 62699]]

SUMMARY: The National Institute of Standards and Technology (NIST) and 
the National Geodetic Survey (NGS), National Ocean Service (NOS), 
National Oceanic and Atmospheric Administration (NOAA), have taken 
collaborative action to provide national uniformity in the measurement 
of length. This notice announces the final decision to deprecate use of 
the ``U.S. survey foot'' on December 31, 2022. Beginning on January 1, 
2023, the U.S. survey foot should not be used and will be superseded by 
the ``international foot'' definition (i.e., 1 foot = 0.3048 meter 
exactly) in all applications. The international foot is currently used 
throughout the U.S. for a large majority of applications and is 
typically referred to as simply the ``foot.'' Over time this 
terminology will become more prevalent in land surveying and mapping 
communities. Either the term ``foot'' or ``international foot'' may be 
used, as required for clarity in technical applications. This notice 
describes public comments received, along with the plan, resources, 
training, and other activities provided by NIST and NOAA to assist 
those affected by this transition.

DATES: Use of the U.S. survey foot will be deprecated on December 31, 
2022.

ADDRESSES: All comments submitted in response to the October 17, 2019, 
Federal Register notice request for public comment may be accessed at 
https://www.regulations.gov, docket number NIST-2019-0003, under the 
``Enhanced Content'' section of the Federal Register web page for that 
notice. Additional U.S. survey foot deprecation resources are available 
at https://www.nist.gov/pml/us-surveyfoot.

FOR FURTHER INFORMATION CONTACT: 
    Information on standards development and maintenance: Elizabeth 
Benham, 301-975-3690, [email protected].
    Technical and historical information on usage of the foot: Michael 
Dennis, 240-533-9611, [email protected].

SUPPLEMENTARY INFORMATION:

Notice of Final Determination

    On October 17, 2019, NIST and NOAA published a notice titled 
``Deprecation of the United States (U.S.) Survey Foot'' in the Federal 
Register (84 FR 55562). In that notice, NIST and NOAA announced the 
initial decision to deprecate the U.S. survey foot and to require that 
its use be discontinued for all applications in the United States, 
including surveying, mapping, and engineering. The intent of this 
action is to provide national uniformity of length measurement in an 
orderly fashion with minimum disruption, correcting a measurement 
dilemma that has persisted for over 60 years. A notice announcing a 90-
day extension of the review and analysis period to address public 
comments was published in the Federal Register (85 FR 41560) on July 
10, 2020, and further indicated that the final determination would be 
published by September 28, 2020.
    After December 31, 2022, any data derived from or published as a 
result of surveying, mapping, or any other activity within the U.S. 
that is expressed in terms of feet should only be based on the 
definition of one foot being equal to 0.3048 meter (exactly). This 
definition was named the ``international foot'' in the 1959 Federal 
Register notice (24 FR 5348) that officially changed the foot 
definition for the U.S. In 1959, the other foot definition was named 
the ``U.S. survey foot,'' with the mandate that it be used only for 
geodetic surveying, and that it be replaced by the international foot 
definition.
    With this notice, the mandate to replace the U.S. survey foot with 
the international foot definition for all applications has been 
achieved, and after December 31, 2022, there will be only one approved 
definition of the foot in the U.S. The preferred term is simply the 
``foot,'' which is the name currently used for most applications. When 
needed to avoid confusion with the U.S. survey foot, use of the term 
``international foot'' is an acceptable synonym for ``foot.''
    The date of December 31, 2022, was selected to accompany the 
modernization of the National Spatial Reference System (NSRS) by NOAA's 
National Geodetic Survey (NGS). The reason for associating the 
deprecation of the U.S. survey foot with the modernization of the NSRS 
is that the biggest impact of the uniform adoption of the international 
foot will be for users of the NSRS, due to very large coordinate values 
currently given in U.S. survey feet in many areas of the U.S. Impacts 
related to the change to international feet will be minimized if a 
transition occurs concurrently with others changes in the NSRS. More 
details on the relationship between the NSRS and deprecating the U.S. 
survey foot were provided in the previous notices, and are discussed 
further later in this notice. This approach provides ample time for the 
surveying and mapping community to plan for and implement related 
changes.
    Modernization of the NSRS was originally planned to occur in 2022. 
However, operational, workforce, and other issues have arisen causing 
NGS to re-evaluate the timing of implementation (see https://geodesy.noaa.gov/datums/newdatums/delayed-release.shtml for details). 
Despite the possibility of delay of the modernization of the NSRS 
beyond 2022, the planned date of December 31, 2022, for deprecation of 
the U.S. survey foot will not change and is independent from the NSRS 
modernization timeline. A benefit of retaining the original date for 
the deprecation of the U.S. survey foot is that it will ensure that it 
will occur prior to the rollout of the modernized NSRS. The difference 
in timelines will have no effect on users of the existing NSRS, because 
NGS will continue to support the U.S. survey foot for components of the 
NSRS where it is used now and in the past. In other words, as explained 
below, to minimize disruption in the use of U.S. survey foot for 
existing NSRS coordinate systems, the change will apply only to the 
modernized NSRS.

Comments Received

    In the October 17, 2019, notice, NIST and NOAA requested comments 
from all interested persons on the announced changes by December 2, 
2019. Seventy-two comments were received in response to that notice. 
The comments received, and this final determination, are available 
online at the ``Regulations.gov'' website (http://www.regulations.gov) 
within Docket No. NIST-2019-0003. The purpose of the solicitation was 
to announce the initial decision to deprecate the U.S. survey foot and 
seek public comments to identify unforeseen issues and facilitate a 
smooth transition to a single definition of the foot. In response, many 
opinions were expressed in support or opposition. Those comments are 
summarized here.
    Because the solicitation did not directly ask for comments in 
support of or in opposition to the planned change, an opinion regarding 
support or opposition was not provided in all of the comments. Of the 
72 responses received, 64 (89 percent) offered such an opinion. Thirty-
four of those 64 comments (53 percent) expressed support for universal 
adoption of the international foot. Twenty-one (33 percent) expressed a 
desire to retain the U.S. survey foot, either for surveying and mapping 
exclusively, or to replace the international foot for all applications. 
Nine (14 percent) preferred eliminating both definitions of the foot 
and instead adopting the meter as the length measurement unit used in 
surveying and mapping. Additional public feedback from sources outside 
this public comment process, but related to NGS U.S. survey foot 
outreach

[[Page 62700]]

activities planned as part of this action, were received from a much 
larger number of people and generally followed the trends described 
later in this section.
    Only four comments were anonymous. Of the 68 commenters who 
provided their names, 28 also identified one or more organization 
affiliation. These consisted of at least one state or county government 
agency in ten states, six professional or business associations, one 
university, and 13 private companies.

1. Comments in Support of Deprecation

    The comments received included statements of support from 
representatives of state government agencies in eight states (i.e., 
Arizona, Iowa, Idaho, Kentucky, Maine, Michigan, Pennsylvania, and 
Washington). No state government expressed opposition to the 
deprecation of the U.S. survey foot.
    The remainder of supportive comments were from individuals, mostly 
surveyors, who agreed that the U.S. survey foot should be discontinued. 
About half of these individuals identified either their employer or the 
organization they represented. The overall theme that emerged from 
public comments was that discontinuing use of the U.S. survey foot 
enhances the value and benefit of national uniformity and minimizes 
opportunities for confusion and unnecessary costs to the users, states, 
and professionals in the surveying, mapping, and engineering fields. 
The following comment excerpts exemplify the reasons for supporting the 
change.
    The elimination of the U.S. survey foot is past due, and the best 
time to implement this change is now, during development of the State 
Plane Coordinate System of 2022 (SPCS2022) as part of the NSRS 
modernization. For example:

    ``We badly need to get rid of this confusing dual definition of 
feet and join with the other five countries (or at least those that 
have not fully converted to metric yet) in that 1959 decision to 
have a single, common definition of the yard [and foot] and pound--
the sooner, the better. Let's not allow survey feet as an option for 
SPCS2022 output, so as to avoid dragging this out years into the 
future.''
    ``The U.S. survey foot should be eliminated. Hard to convert to 
meters and back. A standard international foot will be easier to 
deal with. With the change in datums in 2022 it is the perfect time 
to eliminate it. Here in Michigan we use the international foot and 
it works fine except that some federal agencies report their state 
plane coordinates in U.S. survey feet. End the confusion I say.''
    ``Having the country using only one definition of the foot for 
survey and mapping not only makes good sense, it will [eliminate] 
the possibility of the unintended error [that] currently happens due 
to the dual foot definitions. The timing of a single foot standard 
coinciding with the 2022 readjustment is prudent and well planned.''

    According to the U.S. Bureau of Labor Statistics, a large majority 
of surveyors are employed in the ``Architectural, Engineering, and 
Related Services'' industry, which includes international, national, 
regional, and small firms. A substantial number also work for 
government agencies and in the construction sector. Many surveyors are 
licensed in more than one state, and large projects often include 
surveyors and other geospatial professionals from multiple states. The 
ability to efficiently work in multiple states and across borders 
increases the scope of revenue. The benefits of having a single 
definition for the foot for all states are anticipated to outweigh the 
inconveniences associated with this change. For example:

    ``I am in strong agreement with this decision. Having worked for 
a consultant with offices in both U.S. and International foot 
states, this created real headaches when staff from different 
offices were working on the same projects.''
    ``For many years I worked in multiple states and it was clear 
that many surveyors did not know with which definition of the foot 
they were working. The confusion was not always evident until there 
were blunders related to construction elements. These can be costly. 
I agree with the proposal and say good riddance to the ratio.''
    ``No one need look any further than the infamous Mars Climate 
Orbiter failure to understand why this action is vital to 
eliminating confusion brought about by having multiple choices 
between systems of measure. While the probe failure resulted from 
inadvertent confusion between two systems (metric vs U.S.), this 
issue is even more insidious given once there is an awareness for 
making a unit conversion the process is further complicated by the 
ambiguity created when multiple conversion factors are present 
(International foot vs. U.S. Survey foot in this case). To allow 
this condition to persist when it is no longer necessary would be 
considered intentional neglect by any objective standard.''

    Many small businesses in the United States will benefit from this 
change. Although surveyors and other geospatial professionals work for 
organizations that vary greatly in size, many are independent 
contractors or consultants who work for small firms or are self-
employed. The National Federation of Independent Businesses (NFIB), an 
advocate of small and independent American business owners, expressed 
support for the change:

    ``NFIB [National Federation of Independent Business] is an 
incorporated nonprofit association with about 300,000 small and 
independent business members across America. NFIB protects and 
advances the ability of Americans to own, operate, and grow their 
businesses and, in particular, ensures that the governments of the 
United States and the fifty states hear the voice of small business 
as they formulate public policies. Many businesses, including small 
businesses, depend upon accurate weights and measures in their 
commerce. . . The move to a ``foot'' with a single length everywhere 
and for all purposes in the U.S. will facilitate commerce, public 
safety, and national defense.''

2. Comments Providing Examples of Errors and Costs

    Public comments highlighted significant errors and costs that have 
resulted from two definitions of the foot in use within the surveying 
and mapping community. Several comments addressed examples based on 
their professional experiences:

    ``I am employed by a commercial contractor working on a 
government project in which there was confusion about 3 years ago 
when a simulation program noticeably deviated from real data because 
one used survey feet and the other used international feet. The time 
lost to track down the deviation was significant.''
    ``A roadway alignment is surveyed in international feet using a 
low distortion projection and laid onto a global image under the 
assumption the survey is the U.S. foot definition. Locally all 
alignment points fit well vs. record distance and bearings. However, 
when cast onto the global image map the roadway alignment is 12 feet 
north and 45 feet east of the roadway on the image. The roadway 
construction plans that use global aerial images as a background 
cannot be completed until the surveyed line work is in coincidence 
with the global image.''
    ``I one hundred percent support the deprecation of the U.S. 
Survey Foot as a unit of measure. Having two ``feet'' has cost my 
company and countless others untold amounts of lost time due to 
errors and confusion associated with two separate definitions of the 
foot.''

    Because multiple comments disclosed generic examples of errors and 
the resulting negative impacts during the notice process, NGS took 
action to seek additional examples from the stakeholder community to 
further explore the risk. The action consisted of poll questions asked 
during webinars and providing an email address specifically for input 
([email protected]). A summary of these additional findings is 
available on the U.S. survey foot website (https://www.nist.gov/pml/us-surveyfoot). Multiple organizations and individual surveyors expressed 
to NGS that they are hesitant to disclose specific projects and the 
resulting errors because of liability concerns.

[[Page 62701]]

    For example, one comment included an image from engineering plans 
showing both definitions of the foot, with the State Plane coordinates 
in U.S. survey feet redacted, so that it was not possible to determine 
its actual location. NGS took additional action to clarify this 
submission, which was further described in subsequent email 
correspondence:

    ``[The image is from a] facility drawing for an industrial 
plant, where the plant coordinates are in international feet yet the 
State Plane coordinates of the same points on the same plans were in 
U.S. survey feet. And yet the plant coordinates are forced to be 
identical to the State Plane coordinates at one location, where the 
State Plane easting was over 2,600,000 sft, which causes more than 5 
feet of positional error.''

3. Comments Dealing With Legacy Infrastructure and Data

    Comments highlighted that this measurement unit change is like past 
changes that dealt with legacy infrastructure and data. With planning 
and retention of unit conversion factors, as published by NIST, the 
outcome will be successful. For example:

    ``Many of our older records and plans will not be impacted by 
using one definition over another because their projection basis is 
not global but local and many times completely unknown and 
irrelevant. There will always be legacy records that use [the] U.S. 
foot just as there are legacy records that use the chain unit, rod, 
perch, etc. Those who deal with various units of measure will handle 
the conversions just as they do now if needed.''
    ``Ending the use of the U.S. Survey Foot for state plane 
coordinate systems is long overdue. Definitions and conversion 
factors need to be clear and concise without ambiguity.''
    ``The argument some make that deeds from U.S. foot states would 
need to be translated into international foot distances is weak--
there's only 0.01 ft difference in one mile between the two! How 
many surveyors who make this claim are accounting for the different 
accuracy/precision of equipment when the original deeds where 
surveyed or the various measurement errors present in all 
equipment?''
    ``I favor the elimination of the Survey foot. I would note that 
since 1983 USCGS (now NGS) has allowed states to designate whether 
they use the Survey or International foot in surveying and use in 
their State Plane Coordinate Systems. The two feet, so close in 
value, cause a lot of confusion.''

4. Comments Regarding Use of the Term ``International Foot'' Versus 
``Foot''

    Of the 17 public comments that expressed an opinion on the name of 
the foot after deprecation, 14 favored retaining ``international'' as 
part of the name, rather than simply calling it the ``foot.'' In all 
cases, the reason was to avoid confusion between the types of foot, 
both for legacy and future applications. For example:

    ``Due to all of the historical data held by Federal, State and 
local government agencies as well as private firms, I feel it will 
be a mistake to refer to the International Foot as simply Foot. 
There is already a problem with GIS professionals as well as 
surveyors not documenting datums and units for projects adequately. 
By removing the reminder of which foot new data is presented in, it 
opens up the possibility of further confusion.''
    ``I believe to avoid confusion that upon deprecating the use of 
the term U.S. Survey Foot that we go on to use the terminology of 
International Foot. My reason is people reference the U.S. survey 
foot as a foot. I think that the use of International Foot will 
signify a change is being made. I work with legal descriptions in a 
state that adopted the U.S. Survey Foot and will have to change. If 
we don't differentiate there will be confusion. My fear is that 
simply saying you are adopting the foot will not resonate and may 
lead some to believe that they can continue to use the U.S. Survey 
Foot. Over time the international foot will be referred to as a foot 
again but for technical purposes I think that the differentiation is 
important. At a minimum officially stating the U.S. Survey Foot will 
be superseded by the international foot will work. People will 
casually reference it as a foot anyway.''
    ``To use a term such as ``the foot'' is inconsistent with 
efforts to minimize ambiguities in Surveying documents. If there is 
more than one version of something, then which version is being 
referred to should be made clear.''

5. Comments Supporting Use of the Metric System

    The initial request for public comment noted that states currently 
have the option to select the International System of Units (SI), 
commonly known as the metric system, option for surveying and mapping; 
NGS adopted the metric system in 1977 (54 FR 25318). Although the 
notice did not request public input regarding state adoption of the 
metric option for surveying and mapping, several comments expressed 
this preference. For example:

    ``Rather than deprecating the U.S. Survey foot, I would rather 
see the United States deprecate the use of the foot altogether for 
survey measurements and adopt the meter as the unit of measure.''
    ``The native measurement unit used by modern land surveying 
equipment is the meter. Additional software is required to deal with 
our two archaic units of measurement. On December 31, 2022 the foot, 
in all of its iterations, should be relegated to legacy status.''

6. Comments Opposing Deprecation

    A minority of public comments expressed opposition to the change 
and identified several concerns that will be addressed in the 
deprecation process. The two primary reasons given for supporting 
retention of the U.S. survey foot were that a large amount of legacy 
data and records in that unit already exist, and that a majority of 
states have legislated or otherwise adopted it for surveying.
    Some opposing comments cited erroneous or misleading information, 
or made claims for which no supporting evidence was provided, such as 
conflating the change with conversion to the metric system; stating 
that the U.S. survey foot has always been used for defining boundaries 
in the U.S.; that adopting the international foot would jeopardize 
rights to real property; that the change would be a financial burden; 
and that it creates a problem where none exists.
    All comments opposed to the change were from individuals, except 
for one trade association, the International Association of Oil and Gas 
Producers (IOGP). The IOGP represents 83 member organizations that 
include energy corporations and related associations. Writing on behalf 
of its U.S. members, IOGP advocated to instead adopt the U.S. survey 
foot nationwide, because of its widespread current and historic use in 
the surveying community.
    Considered collectively, the opposing comments recommended to 
instead pursue one of the following three alternatives: 1) keep the 
current approach, where each state chooses its preferred definition of 
the foot; 2) adopt the U.S. survey foot for all geospatial 
applications, and the international foot for everything else; and 3) 
deprecate the international foot and use the U.S. survey foot for 
everything. These alternatives, together with the reasons given for 
opposing adoption of the international foot, are addressed later in 
this notice.

Supplemental Feedback

    During planned outreach efforts, described in the October 17, 2019, 
notice, additional stakeholder feedback was received. NGS presented two 
webinars on deprecating the U.S. survey foot. The first was on April 
25, 2019, ``Fate of the U.S. Survey Foot after 2022: A Conversation 
with NGS,'' and the second was on December 12, 2019, ``Putting the Best 
`Foot' Forward: Ending the Era of the U.S. Survey Foot.'' Both webinars 
were recorded and are available for download (https://geodesy.noaa.gov/web/science_edu/webinar_series/2019-webinars.shtml), together with the 
companion slides. The webinars provided an overview of the history of 
the survey foot, discussed examples of problems encountered, summarized 
the public comments

[[Page 62702]]

received in response to the previous Federal Register notice, and 
discussed charting a path forward as part of modernizing the NSRS.
    Significant feedback occurred during the two NGS webinar events, 
which were attended by nearly 1,400 unique participants from every 
state, the District of Columbia, Puerto Rico, Guam, and Canada. Webinar 
polls reinforced the public comments obtained through the notice 
process. Figures 1 through 4 summarize feedback from the public comment 
process, webinar participants, and emails sent directly to NGS and NIST 
(with the number from each source given in the figures). Figure 1 
reveals that about twice as many of the 540 respondents (63 versus 33 
percent) have experienced problems due to the existence of the two 
definitions of the foot. This is a striking result that illustrates the 
impact of this problem.
    In terms of solving the foot confusion problem, Figure 2 shows that 
a much larger proportion (58 percent of 730 respondents) prefer 
adopting the international foot, compared to 20 percent in favor of 
keeping the U.S. survey foot, which is slightly less than the number 
who prefer using meters (22 percent).
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    When respondents were asked which name they prefer for the foot 
after deprecation, 39 percent of the 634 respondents preferred 
retaining the name ``international foot'' as shown in Figure 3, rather 
than just ``foot'' (32 percent), or allowing the use of both names (16 
percent). Only a small proportion (9 percent) felt that an entirely new 
name should be used. Combining the preference for the name ``foot'' and 
allowing both names represents 48 percent of the responses. There is 
nonetheless a large number who prefer keeping the modifier 
``international.''
    Preference for the name ``international foot'' in the future is 
explained to a large extent by Figure 4, which summarizes the 
occupations of the people providing feedback. A large majority are in 
the category of ``land surveyor or engineer'' (79 percent of 544 
respondents), with the next largest group in the ``GIS or mapping 
user'' category (11 percent). Land surveyors, civil engineers, mappers, 
and geographic information system (GIS) professionals are typically 
familiar with the existence of these two definitions of the foot.
    The high representation of engineers, GIS professionals, mappers, 
and especially surveyors also helps explain the large proportion of 
respondents who have experienced problems with the two definitions of 
the foot, as shown in Figure 1. This illustrates that NGS outreach 
webinar participants were highly representative of the stakeholder 
community.
    The primary objective of seeking public comment was to get input on 
the process of implementing the change, not whether to make the change. 
To that end, valuable feedback was received regarding continued use of 
the name ``international foot'' after deprecation, rather than simply 
the ``foot.'' This input made a difference and was incorporated into 
the final determination. Considering all feedback received, a 
significant majority of commenters and webinar participants support 
deprecation of the U.S. survey foot and its replacement with the 
international foot definition. This is a noteworthy result because a 
majority of states currently use the U.S. survey foot for surveying and 
mapping. Receiving strong support for deprecating the U.S. survey foot 
reinforces the importance of undertaking this process.

National and State Action Supporting U.S. Survey Foot Deprecation

    Surveyors are by far the most affected by a change in the foot 
definition, so obtaining support and input from national surveying 
organizations was an important part of the deprecation process. The 
National Society of Professional Surveyors (NSPS) and the Utility 
Engineering and Surveying Institute (UESI) of the American Society of 
Civil Engineers (ASCE) are nationwide organizations with a robust 
presence in the surveying profession.
    Although these organizations did not provide input during the 
public comment period, they subsequently stated support for adopting 
the international foot definition for all applications throughout the 
United States (https://www.nist.gov/pml/us-surveyfoot). NSPS has 15,000 
members and is affiliated with state surveying associations in every 
state, the District of Columbia, and Puerto Rico. UESI is an institute 
of 3,300 members within ASCE (with a total of 150,000 members). The 
UESI President expressed that:

    ``UESI believes that having a single definition for the foot 
will reduce confusion in surveying engineering projects, especially 
projects that make use of coordinates with large values (e.g., the 
State Plane Coordinate System). Deprecating the U.S. survey foot 
will minimize costly mistakes that have occurred over the decades 
due to the confusion of having two definitions for the foot.''

    The American Association for Geodetic Surveying (AAGS) is a 
national surveying organization with 150 members that provided input 
through the public comment process. AAGS took a neutral stance and did 
not endorse either definition of the foot but instead endorsed use of 
the meter.
    Because many states have specified the U.S. survey foot for 
surveying applications in statute, it is noteworthy that two such 
states have already adopted the international foot in new legislation: 
Kentucky and Washington. For both states, the legislation went into 
effect this year (2020). The early and proactive action by these states 
has prepared them to switch to the international foot definition when 
the NSRS modernization goes into effect.

[[Page 62705]]

Counterpoints to Feedback Expressing Opposition

    As discussed in the comments section of this notice, some of the 
public responses to the October 17, 2019, notice opposed deprecating 
the U.S. survey foot. Mitigating actions and supporting explanations 
are summarized below that address the concerns expressed in the 
opposing comments. More details are available on the NIST U.S. survey 
foot website (https://www.nist.gov/pml/us-surveyfoot).
    1. Association of the change with NSRS modernization. To minimize 
disruption in the use of U.S. survey feet for existing NSRS coordinate 
systems, the change will apply only to the modernized NSRS. This will 
help with management of the large body of existing data and 
applications based on U.S. survey feet, because only the international 
foot definition will be available after modernization. Therefore, 
knowing the coordinate system will implicitly identify the type of 
foot. Although implementation of NSRS modernization will likely occur 
after the deprecation date of December 31, 2022, the difference in 
timelines will have no effect on use of the U.S. survey foot for the 
existing NSRS, as described in the next item.
    2. Continued support of the U.S. survey foot for historical and 
legacy applications. Support for the U.S. survey foot will be 
maintained in NGS products and services where its use is already 
defined, most notably for existing and previous versions of State 
Plane. Such tools will help users of legacy datasets, as described in 
the previous item.
    3. Uniformity for all users of the U.S. customary system. Although 
surveyors in most states use the U.S. survey foot, they represent a 
small proportion of usage within the U.S. As announced in 1959 (24 FR 
5348), the international foot definition is required for all other 
users of the U.S. customary system of measurement. Adopting a single 
definition of the foot will ensure consistency for all applications, as 
intended in the 1959 notice and required for uniform standards of 
measure.
    4. Reduction in errors. A uniform nationwide definition of the foot 
will reduce errors due to accidental usage of the wrong foot 
definition. Numerous examples of such errors were provided during the 
outreach conducted for this notice, and about twice as many respondents 
said it has caused them problems than said it has not (see Figure 1). 
Operating with two definitions of the foot leads to a systematic 
overhead cost that never ends because of the ever-present risk for 
mistakes. Over time, deprecation of the U.S. survey foot will reduce 
costs in this field of measurement.
    5. No evidence of negative effects for real property. Some feedback 
included claims that deprecating the U.S. survey foot would increase 
costs and mistakes in performing boundary surveys and would burden the 
conveyance and enjoyment of real property. However, no evidence was 
provided in support of this claim. In contrast, six states changed from 
the U.S. survey foot to the international foot in the late 1980s and 
early 1990s. None provided evidence, anecdotal or otherwise, of any 
such negative impacts. This is expected, since the 2 parts per million 
difference in length (approximately 0.01 foot per mile) is too small to 
be of practical consequence for the vast majority of boundary 
determinations.
    6. This change is not comparable to adoption of the metric system 
(SI). Some responses cited previous purportedly unsuccessful and 
disruptive attempts to migrate to SI as a reason not to pursue this 
change, but this analogy is weak. Universal adoption of the 
international foot definition is not a change in the unit of measure. 
Other than for surveying, the international foot is already in use for 
nearly all applications where the U.S. customary system of measurement 
is used. This change is instead a long overdue standardization of the 
foot through deprecation of an older definition used only for a 
specific application, as intended in the 1959 notice.
    Some of the comments expressing opposition to the change included 
proposals for one of three alternatives to deprecating the U.S. survey 
foot, each of which is addressed below.
    1. Define the NSRS only using the metric system (SI) and allow each 
state to choose its preferred foot definition. This alternative is a 
continuation of what is already being done, which has clearly led to 
confusion and errors and is at odds with the objective of uniform 
standards.
    2. Adopt the U.S. survey foot nationwide for all geospatial 
applications, and the international foot for everything else. This 
alternative was also proposed in a 1988 notice (53 FR 27213) but never 
adopted. In addition to conflicting with the intent of uniform 
standards, this alternative would be extremely difficult, and perhaps 
impossible, to apply in practice. It would require that data and 
activities be classified as to whether they are ``geospatial,'' which 
is a problematic and subjective task, given the ambiguity of such 
categorization in many instances. This problem is compounded for data 
and activities that change over time, or that are integrated together 
such that some parts are classified as geospatial and some are not. The 
task of classification itself would place a burden (cost) on 
participants and increase risk due to errors, disagreements, and 
inconsistencies.
    3. Deprecate the international foot and instead use the U.S. survey 
foot for everything. This alternative is not viable because the 
international foot definition is the long-established standard for the 
foot (since 1959). In addition, the international foot is well 
established and in widespread use within the U.S. economy by a large 
majority of the population.

Transition Best Practices and Change Management Planning

    Because the U.S. survey foot is specified for surveying activities 
in statute for most states, an important part of the implementation 
process is updating statutes. NSPS, AAGS, and NGS have collaborated to 
create template legislation to aid state adoption and transition to the 
international foot. State government stakeholders are encouraged to 
review and customize the language, as needed. These legislative 
resources are available online, including statutory text that has 
already been proposed or enacted by states (https://www.ngs.noaa.gov/datums/newdatums/GetPrepared.shtml).
    In researching and developing the U.S. survey foot deprecation 
action plan, no government or professional organization reported 
initiating plans or establishing working groups specifically to address 
deprecation of the U.S. survey foot. However, many groups have 
organized groups to prepare for the NSRS modernization, especially at 
the state level. These groups typically consist of state departments of 
transportation, GIS or cartographer offices, professional surveying 
societies, universities, and other geospatial groups. There has also 
been considerable activity among national organizations and federal 
agencies (as illustrated by the example in the following paragraph). 
From the perspective of these various groups, adoption of the 
international foot is but one relatively small part of the many changes 
that will occur with NSRS modernization. Therefore, they are bundling 
multiple technical issues together as a single change management task.

[[Page 62706]]

    The activities underway throughout the U.S. in planning for NSRS 
modernization are too numerous to report here. As an example, NGS 
solicited input for development of SPCS2022. Formal requests and 
proposals regarding SPCS2022 were received from about 200 different 
stakeholder groups in 41 states, and additional requests were received 
from several federal agencies (e.g., U.S. Geological Survey, National 
Park Service, U.S. Bureau of Reclamation) and an American Indian tribe 
(the Navajo Nation). Importantly, these requests and proposals directly 
reference current NGS Policy, which states that only the international 
foot will be supported for SPCS2022 (and all other components of the 
modernized NSRS). Therefore, all of the organizations providing these 
submittals are also taking action on deprecation of the U.S. survey 
foot, since it is an explicit part of NSRS modernization. This 
demonstrates a high level of national engagement, which bodes well for 
a smooth transition to the international foot as part of implementing 
the modernized NSRS.
    Planning for the change early will minimize unnecessary cost and 
reduce complications and uncertainty. One factor reducing the 
uncertainty is the fact that this change has already occurred in six 
``early adopter'' states (i.e., Arizona, Michigan, Montana, North 
Dakota, Oregon, and South Carolina). These states made the change from 
the U.S. survey foot to the international foot in the late 1980s and 
early 1990s. As with the future change described in this notice, this 
previous one was associated with a change in the NSRS, and for the same 
reason: To minimize disruption by combining the changes. NGS and NIST 
have contacted these states to identify problems encountered, best 
practices, and lessons learned as part of that transition.
    Based on the state responses received so far, the change was 
efficiently managed in the same manner as recommended now, by combining 
the change in the foot definition with the change of the NSRS. Statute 
changes were also enacted by the ``early adopter'' states to specify 
the international foot. However, ongoing problems with the wrong 
definition of the foot being used were reported, usually by surveyors 
from other states still using the U.S. survey foot. The fact that such 
problems continued to occur reinforces the need to uniformly adopt this 
change. As more feedback is received, it will be added to the U.S. 
survey foot website (https://www.nist.gov/pml/us-surveyfoot).
    A significant part of the input received concerned the name to use 
for the foot after deprecation. The October 17, 2019, notice stated 
that the international foot definition would be referred to as simply 
the ``foot.'' A large proportion of feedback preferred retaining the 
name ``international feet'' (see Figure 3 and the associated 
discussion). However, a somewhat larger proportion preferred either 
``foot'' or both names. In addition, the NSPS Directors voted to use 
the term ``foot,'' and UESI also implied that the term ``foot'' was 
acceptable. Finally, a large majority of people in the U.S. only use 
the term ``foot'' for the international foot, in both casual and 
technical contexts, with most being unaware that the U.S. survey foot 
definition exists.
    Nonetheless, it is completely understandable that many surveyors 
prefer to retain the name ``international foot,'' since they must deal 
with both definitions of the foot even after deprecation and 
implementation of the modernized NSRS. Although the use of the U.S. 
survey foot will diminish over time, it will be present for the 
foreseeable future because of legacy data and records, and with it the 
risk for confusion. For that reason, NIST and NOAA recommend continued 
use of the term ``international foot'' in situations where such 
ambiguity is possible.
    States may choose the measurement unit for mapping (metric or 
``foot'') appropriate for their needs. Since the publication of the 
October 17, 2019, notice, two states (i.e., Kentucky and Washington) 
have specified the international foot definition for SPCS2022 and 
related surveying activities. Kentucky continues to use the term 
``international foot'' in its new statute, together with the numerical 
definition. In part, this is because the statute also includes the U.S. 
survey foot, since it is associated with State Plane prior to SPCS2022. 
In contrast, the new Washington statute makes no mention of prior State 
Plane and does not include the word ``international.'' Instead it says, 
``[w]hen the values are expressed in feet, one foot equals 0.3048 
meters, must be used as the standard foot. . . .'' The language in the 
Washington statute is similar to the previously mentioned template 
legislation, which says, ``[w]hen the values are expressed in feet, a 
definition of 1 foot = 0.3048 meter exactly must be used.'' As these 
examples show, the wording and terminology used in legislation will 
depend on each state's specific situation and preferences. The 
paramount objective should be to avoid ambiguity and achieve national 
uniformity.

Implementation Summary and Actions

    NIST and NOAA will implement deprecation of the U.S. survey foot as 
described in the October 17, 2019, notice. The change will enter into 
force on December 31, 2022. This decision will allow adoption of a 
single, uniform definition of the foot for all applications throughout 
the United States. Uniformity in measurement will increase efficiency 
and reduce errors that occur when two nearly identical definitions of 
the foot are in current use. As shown by the public comments received, 
such problems are both common and costly. Moreover, a significant 
majority of input expressed approval of this change, and most of the 
input was received from the groups most affected (i.e., surveyors and 
engineers). In addition, NIST and NOAA note that the benefits of the 
change outweigh the temporary inconveniences, such as the existence of 
a large amount of data and records in U.S. survey feet, and the current 
dominance of its use in the surveying profession. These concerns will 
be mitigated by the actions described in this notice. Other concerns 
were based in misconceptions or lacked supporting evidence, as 
discussed previously.
    In keeping with the terms of this notice, the U.S. survey foot will 
not be supported by NGS in the modernized NSRS, including for SPCS2022, 
elevations, or any other components of the system. Nevertheless, action 
will be taken by NGS to mitigate disruption caused by this change. 
Chief among those is that the U.S. survey foot will be maintained in 
NGS products and services in legacy applications, for example the 
computation of coordinates in States where it was specified for the 
State Plane Coordinate System of 1983, and for all zones of the State 
Plane Coordinate System of 1927.
    Although the International System of Units (SI) is the preferred 
measurement system for trade and commerce in the United States, U.S. 
trade practice may continue to use non-SI measurement units, such as 
the U.S. customary system of measurement. Accordingly, NIST is adopting 
the proposed changes regarding deprecation of the U.S. survey foot and 
replacement with the international foot definition for all applications 
of the U.S. customary system of measurement in the U.S. The 
relationship between SI length measurement units and the U.S. survey 
foot and associated non-SI units will be incorporated in the upcoming 
edition of NIST Special Publication (SP) 811, Guide for the Use of the 
International System of Units (SI) before December

[[Page 62707]]

31, 2022. The preferred measurement unit of length is the meter, and 
surveyors, map makers, and engineers are encouraged to adopt the SI for 
their work. NIST recognizes that the foot and its derivative measures 
are in widespread use, and therefore NIST SP 811 will provide 
clarifying technical guidance regarding the foot and other non-SI 
length measurement units.
    Past editions of NIST SP 811 and other NIST publications provided 
relationships for several traditional linear units that were based only 
on the U.S. survey foot. Table 1 provides the exact foot definitions 
for these units. Of the units listed, only the foot itself, the mile, 
and the square mile also had international foot definitions in previous 
editions of NIST SP 811 and other NIST publications. Future editions 
will include international foot definitions for all of these 
traditional linear units.
    Table 1 gives conversions to meters for both foot definitions, 
which are exact for the international foot and approximate for the U.S. 
survey foot. Although U.S. survey foot conversions are included, their 
use should be avoided after December 31, 2022, other than for historic 
and legacy applications.
    The foot-based units in Table 1 have traditionally been used for 
land measurement and surveying, except for the cable's length and 
fathom (used for water depth). Maintaining these exact foot 
relationships to the international foot definition is essential, 
because at least some of these units are still widely used in surveying 
practice (such as the acre and chain), and that usage will continue as 
long as the foot is used. In addition, these units have also been 
computed using the international foot since the late 1980s in those 
areas where the international foot was adopted. For these traditional 
measures, the difference between the two types of feet is usually of 
negligible consequence in most practical applications. For example, the 
greatest precision typically used for the chain in modern land 
surveying practice is three decimal places (or 0.1 link), and at that 
level of significance both definitions of the foot give the same value. 
Similarly, the difference in area for 1 acre is only 0.000 004 acre 
(about 0.17 ft\2\ or 25 square inches) for the two definitions of the 
foot. Nonetheless, from a metrological perspective, documenting the 
formal definitions based on the international foot is essential to 
avoid ambiguity, hence their inclusion in this notice and future 
editions of NIST SP 811.

 Table 1--Exact Relationships for Units of Measure Based on the Foot, Including Exact Conversions to Meters for
 the International Foot and Approximate Conversions to Meters for the U.S. Survey Foot, as Will Be Published in
  the 2020 Edition of NIST SP 811, Guide for the Use of the International System of Units (SI). Except for the
            Mile and Square Mile, These Units Were Previously Only Defined With the U.S. Survey Foot
----------------------------------------------------------------------------------------------------------------
                                                Exact U.S. customary
  Units based on the                            definitions based on   International foot     U.S. survey foot
         foot                 Unit type         the foot, plus other    metric equivalent     metric equivalent
                                                 exact definitions           (exact)            (approximate)
----------------------------------------------------------------------------------------------------------------
foot (ft).............  length...............  Defined with respect   0.3048 m............  0.304 800 609 601 m.
                                                to meter.
cable's length........  length...............  720 ft = 120 fathoms.  219.456 m...........  219.456 438 913 m.
chain (ch)............  length...............  66 ft = 4 rd = 100 li  20.1168 m...........  20.116 840 234 m.
fathom................  length...............  6 ft.................  1.8288 m............  1.828 803 658 m.
furlong (fur).........  length...............  660 ft = 10 ch = 40    201.168 m...........  201.168 402 337 m.
                                                rd.
league................  length...............  15,840 ft = 3 mi.....  4828.032 m..........  4828.041 656 083 m.
link (li).............  length...............  0.66 ft = 0.01 ch....  0.201 168 m.........  0.201 168 402 m.
mile (mi) (a).........  length...............  5280 ft = 8 fur = 80   1609.344 m..........  1609.347 218 694 m.
                                                ch = 320 rd.
rod (rd), pole, perch.  length...............  16.5 ft = 0.25 ch....  5.0292 m............  5.029 210 058 m.
acre (ac).............  area.................  43,560 ft\2\ = 10      4046.856 422 4 m\2\.  4046.872 609 874
                                                ch\2\ = 160 rd\2\.                           m\2\.
square mile (mi\2\)...  area.................  27,878,400 ft\2\ =     2 589 988.110 336     2 589 998.470 319
                                                640 ac.                m\2\.                 521 m\2\.
acre-foot.............  volume...............  43,560 ft\3\.........  1233.481 837 547 52   1233.489 238 468 149
                                                                       m\3\.                 m\3\.
----------------------------------------------------------------------------------------------------------------
(a) Also referred to as the ``statute mile.'' Although historically defined using the U.S. survey foot, the
  statute mile can be defined using either definition of the foot, as is the case for all other units listed in
  this table. However, use of definitions based on the U.S. survey foot should be avoided after December 31,
  2022 except for historic and legacy applications.

Recommendations To Facilitate the Change

    NIST and NOAA make the following recommendations to facilitate the 
orderly transition to a uniform adoption of the definition 1 foot = 
0.3048 meter exactly for all applications in the United States:
     Begin the process now. States, other government agencies, 
businesses, private and public organizations, and all others 
potentially impacted by this change should take immediate steps to 
begin planning for the transition. Early action is important, since 
some changes can be time intensive, such as enacting state legislation 
or updating software, training materials and relevant procedures.
     Use nationally developed template resources for updating 
state statutes. NSPS, AAGS, and NGS have collaborated to create 
template legislation to aid state adoption and transition to the 
international foot. Template legislation and examples of actual 
statutes are available for download at https://geodesy.noaa.gov/datums/newdatums/GetPrepared.shtml. State government stakeholders are 
encouraged to review and customize the language in this template and 
these examples, as needed.
     Consult the current edition of NIST SP 811 for updating 
software and publications. NIST SP 811 is the authoritative source for 
exact and appropriate unit conversion factors. As part of preparing for 
implementation of this change, software developers and others who 
perform conversions should consult and use the current edition of NIST 
SP 811 to ensure the correct definitions are being used.
     Use the foot name most appropriate to your needs. 
Confusion may occur when comparing modern measurements with historical 
records that use legacy terminology, or any other situation where it 
can be unclear as to which

[[Page 62708]]

definition of the foot was used. To minimize such ambiguity and prevent 
misunderstandings, NIST and NOAA recommend using the term 
``international foot'' or specifically identifying the metric 
conversion of 1 foot = 0.3048 m exactly.
     Always document the units used for quantitative work. 
Complete and correct documentation of measurement units is an essential 
part of any quantitative work. It is particularly important for 
situations where confusion can occur, such as between the U.S. survey 
and international foot definitions.
     Use consistent abbreviations for the types of foot. 
Following deprecation, the standard lowercase abbreviation ``ft'' will 
refer to the international foot definition by default. Likewise, the 
abbreviations in Table 1 for all units derived from the foot will also 
be based on the international foot definition. Although absence of a 
prefix indicates an international foot definition, situations will 
occur where an abbreviation that clearly identifies the foot definition 
is necessary to avoid confusion, such as in surveying and mapping. In 
such cases, the abbreviation for the international foot definition 
should be preceded by a lower case ``i'' as ``ift'' to ensure clarity. 
The abbreviation for the U.S. survey foot should always be preceded by 
a lower case ``s'' as ``sft'' for all applications. For abbreviation of 
units derived from the U.S. survey foot, the ``s'' prefix should be 
used as needed to avoid confusion, for example ``smi'' for mile, 
``sch'' for chain, and ``sac'' for acre. However, this may not be 
necessary if the type of foot is obvious from the context or is 
otherwise clearly documented.
     Avoid use of the terms ``Imperial'' or ``British'' to 
describe the U.S. customary system. In common parlance, the terms 
``Imperial'' or ``British'' are often used to represent the traditional 
units used within the U.S; however, because there are significant 
differences between many of these traditional measurement systems, NIST 
recommends use of the term ``U.S. customary system of measurement'' to 
describe the collection of non-SI measurement units currently used in 
the U.S. This parlance is frequently incorrectly employed in software, 
on websites, and in publications. To further eliminate this common 
misunderstanding between U.S. customary measurement units and British 
and Imperial units, additional explanation of the differences are 
provided in NIST Handbook (HB) 44, ``Specifications, Tolerances, and 
Other Technical Requirements for Weighing and Measuring Devices,'' 
Appendix B, ``Units and Systems of Measurement'' (https://www.nist.gov/pml/weights-and-measures/publications/nist-handbooks/other-nist-handbooks/other-nist-handbooks-2-2).
    Implementing these recommendations, together with other mitigating 
actions being taken by NIST and NOAA, will facilitate the smooth 
transition and nationwide adoption of the international foot with 
minimal disruption. Additional resources providing greater detail about 
the history of the foot, problems encountered by having two definitions 
of the foot, and the benefits of making this change are available on 
the NIST U.S. survey foot website (https://www.nist.gov/pml/us-surveyfoot).
    Authority: 15 U.S.C. 272(b) & (c).

Nicole R. LeBoeuf,
Acting Assistant Administrator for Ocean Services and Coastal Zone 
Management, National Ocean Service.
Kevin A. Kimball,
Chief of Staff, National Institute of Standards and Technology.
[FR Doc. 2020-21902 Filed 10-2-20; 8:45 am]
BILLING CODE 3510-13-P