[Federal Register Volume 63, Number 6 (Friday, January 9, 1998)]
[Notices]
[Pages 1422-1425]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-544]


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DEPARTMENT OF COMMERCE

Bureau of the Census
[Docket No. 970408082-7273-02]


Block Group Program for Census 2000--Final Criteria

AGENCY: Bureau of the Census, Commerce.

ACTION: Notice of final program.

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SUMMARY: Block groups are geographic statistical divisions of census 
tracts, each of which consists of from one to nine block groups. A 
block group comprises a reasonably compact and contiguous cluster of 
census blocks. The

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primary goal of the block group program is to provide data users with a 
geographic subunit of census tracts for which decennial census sample 
and 100 percent data are tabulated and disseminated.
    The Census Bureau first used block groups in its data presentations 
from the 1970 census. It did this in lieu of providing data summaries 
for enumeration districts in areas that had census block numbers. As 
census blocks and block groups became increasingly popular with data 
users, the Census Bureau established them in many new areas. By 1990, 
there was complete census block and block group coverage for all of the 
United States, Puerto Rico, and the Island Areas (American Samoa, Guam, 
the Northern Mariana Islands, and the Virgin Islands of the United 
States).
    Through the 1990 census, block groups were subunits either of 
census tracts or of statistically equivalent entities known as block 
numbering areas (BNAs). For areas where census tracts did not exist, 
the Census Bureau had established BNAs to control the numbering of 
census blocks within block groups. A county or statistically equivalent 
entity 1 could, therefore, have either census tracts or 
BNAs. For Census 2000, the Census Bureau will combine the similar 
programs into a single census tract program.
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    \1\  Includes parishes in Louisiana; boroughs and census areas 
in Alaska; independent cities in Maryland, Missouri, Nevada, and 
Virginia; that portion of Yellowstone National Park in Montana; 
districts/islands in American Samoa and the main islands of the 
Virgin Islands of the United States; municipalities in the Northern 
Mariana Islands; municipios in Puerto Rico; the entire area 
constituting the District of Columbia; and the entire area 
constituting Guam. This notice will refer to all these entities 
collectively as ``counties.''
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    To determine boundaries and identification numbers for block 
groups, the Census Bureau offers a program to local participants, such 
as locally identified agencies and American Indian tribal officials and 
Alaska Native officials, whereby they can review and update the 
boundaries of the block groups delineated for the 1990 census and 
suggest revisions according to the criteria developed and promulgated 
by the Census Bureau. The Census Bureau will then review the resulting 
block groups for conformance to these criteria. The Census Bureau does 
not take into account or attempt to anticipate any nonstatistical uses 
that may be made of block groups, nor will the Census Bureau modify the 
definition of block groups to meet the requirements of any 
nonstatistical program.
    The Census Bureau is now publishing final criteria for the 
delineation of block groups for Census 2000. These criteria will apply 
to the 50 states, American Indian and Alaska Native areas, Puerto Rico, 
and the Island Areas. The Census Bureau may modify and, if necessary, 
reject proposals for block groups that do not meet the criteria 
established following this notice.
    In addition to these final criteria, this notice includes a 
description of the changes from the criteria used for the 1990 census 
and a list of definitions of key terms used in the criteria.

DATES: The Block Group criteria for Census 2000 become effective 
February 9, 1998.

ADDRESSES: Director, Bureau of the Census, Washington, DC 20233-0001.

FOR FURTHER INFORMATION CONTACT: Dr. Joel Morrison, Chief, Geography 
Division, Bureau of the Census, Washington, DC 20233-7400, telephone 
(301) 457-1132, or e-mail ([email protected]).

SUPPLEMENTARY INFORMATION: The block group delineation criteria have 
evolved in response to decennial census practices and the preferences 
of program participants and data users. After each decennial census, 
the Census Bureau, in consultation with participants and data users, 
reviews and revises these criteria. Then, before the next decennial 
census, the Census Bureau offers state, tribal, and local officials an 
opportunity to correct, update, and otherwise improve the block group 
delineations.
    In July and August 1995, the Census Bureau issued invitations to 
local and tribal groups and agencies to participate in the delineation 
of statistical geographic areas for Census 2000. These groups and 
agencies included regional planning agencies, councils of governments, 
county planning agencies, officials of federally recognized American 
Indian tribes, and officials of the 12 nonprofit Alaska Native Regional 
Corporations.
    By early 1998, the Census Bureau will provide maps and detailed 
guidelines to program participants for the review and delineation of 
block groups for Census 2000.

Response to Comments

    The Census Bureau issued a Notice of Proposed Program Revisions and 
Request for Comments in the Federal Register (62 FR 24077) on Friday, 
May 2, 1997. That notice solicited comments on the proposed criteria 
for delineating block groups for Census 2000. The Census Bureau 
received only one comment--from a county planning department requesting 
the continued use of housing unit estimates rather than population 
estimates as a basis for proposing block groups. In response, the 
Census Bureau expressed its willingness to accept block group proposals 
based on housing unit estimates. The Census Bureau is maintaining its 
population-based criteria and will apply a standard figure (2.5 persons 
per household) to convert housing units to population estimates.

Executive Order 12866

    This notice does not meet the criteria for a ``significant 
regulatory action'' as specified in E.O. 12866.

Regulatory Flexibility Act

    Pursuant to the provisions of the Regulatory Flexibility Act (5 
U.S.C. 605(b)), the Assistant General Counsel for Legislation and 
Regulation, Department of Commerce, certified to the Chief Counsel, 
Small Business Administration, that this notice will not have a 
significant economic impact on a substantial number of small entities. 
This notice sets forth the criteria for the delineation of block groups 
for Census 2000. The criteria will be used to provide geographic 
subunits of census tracts for the tabulation of census data. Thus, 
because the Census Bureau uses block groups to tabulate and disseminate 
statistical data from the decennial census, the delineation of block 
groups is solely for statistical purposes. It will not have a 
significant economic impact on a substantial number of small entities.

Final Program Requirements

A. Criteria for Delineating Block Groups for Census 2000

    The Census Bureau announces the following final criteria for use in 
delineating Census 2000 block groups:
1. General Characteristics
     A block group must meet the population and boundary 
feature criteria and comprise a compact piece of territory.
     A census tract boundary always must be a block group 
boundary.
     Each census tract must contain a minimum of one block 
group and may have a maximum of nine block groups.
     Block groups must cover the entire land and inland water 
area of a census tract.
     A block group entirely within an American Indian 
reservation may extend across a state or county boundary for 
tabulations in the American Indian geographic hierarchy. For standard 
data tabulations, the portion of the block group in each state and 
county is treated as a separate block group.

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2. Identification
     A block group consists of all blocks within a census tract 
that have the same first digit and is identified using that same first 
digit. For example in 1990, block group 3 included all census blocks 
numbered in the 300s. For Census 2000, the Census Bureau will introduce 
a four-digit block numbering system, and block group 3 will include all 
census blocks numbered in the 3000s within a census tract.
     The range of acceptable block group numbers is 1 through 
9. Block group numbers must always be unique within a census tract; 
that is, the same number cannot be repeated.
     The Census Bureau will assign a single ``zero'' block 
group to census tracts numbered ``0000.'' (In counties that have 
coastal water, territorial sea, or Great Lakes waters, the Census 
Bureau recommends establishing a ``0000'' census tract to provide 
complete area coverage.)
3. Boundary Features
    The Census Bureau recommends that block group boundaries follow 
visible and identifiable features; that is, visible, perennial natural 
and cultural features, such as roads; rivers; canals; railroads; above-
ground, high-tension power lines; and so forth. This provision makes 
the location of boundaries less ambiguous and easier for data users to 
locate.
    State and county boundaries are always block group boundaries. The 
Census Bureau also permits the use of other types of legal boundaries 
in some states and situations where the boundaries of these 
governmental units tend to remain unchanged between censuses. The 
following features are acceptable as block group boundaries:
     American Indian reservation and trust land boundaries.
     All minor civil division (MCD) boundaries (generally towns 
or townships) in Connecticut, Indiana, Maine, Massachusetts, New 
Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and 
Vermont.
     Those MCD boundaries not conjoint with the boundaries of 
incorporated places that themselves are MCDs (being either coextensive 
with or independent of MCDs) in Illinois (townships only, not election 
precincts), Iowa, Kansas, Michigan, Minnesota, Missouri (governmental 
townships only), Nebraska (townships only, not election precincts), 
North Dakota, Ohio, South Dakota, and Wisconsin.
     Barrio, barrio-pueblo, and subbarrio boundaries in Puerto 
Rico, census subdistrict boundaries in the Virgin Islands of the United 
States, MCD-county and island boundaries in American Samoa, municipal 
district boundaries in the Northern Mariana Islands, and election 
district boundaries in Guam.
     All incorporated place boundaries in Connecticut, Maine, 
Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode 
Island, and Vermont.
     Conjoint incorporated place boundaries in other states; 
that is, the boundary separating two different incorporated places.
     Alaska Native village statistical area and Alaska Native 
Regional Corporation boundaries, at the discretion of the Census 
Bureau, insofar as such boundaries are unambiguous for allocating 
living quarters as part of Census 2000 activities.
    When the above types of features are not available for selection, 
the Census Bureau may, at its discretion, approve other nonstandard 
visible features, such as ridge lines, pipelines, intermittent streams, 
fence lines, and so forth. The Census Bureau also may accept, on a 
case-by-case basis, the boundaries of selected nonstandard and 
potentially nonvisible features, such as the boundaries of national 
parks and national forests, cemeteries, or other special land-use 
properties; the straight-line extensions of visible features; and other 
lines of sight.
4. Population Thresholds
    The Census Bureau has established standard size criteria for most 
block groups in the United States, Puerto Rico, and the Island Areas 
(American Samoa, Guam, the Northern Mariana Islands, and the Virgin 
Islands of the United States). (See Table 1.) Smaller optimum and 
minimum sizes are permissible for block groups located on American 
Indian reservations or comprising special places. (Special places are 
correctional institutions, military installations, college campuses, 
workers' dormitories, hospitals, nursing homes, and group homes.)

      Table 1.--Population Thresholds for Census 2000 Block Groups      
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             Area(s)                 Optimum      Minimum      Maximum  
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United States, Puerto Rico, and                                         
 the Island Areas................        1,500          600        3,000
American Indian reservations.....        1,000          300        3,000
Special place block group........         None          300        None.
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    If a block group located on an American Indian reservation crosses 
a county boundary or a state boundary, the minimum population size 
criterion applies to the entire area of the block group, not to the 
individual portions that are in separate counties or states.
5. Final Approval of Block Groups
    The Census Bureau reserves the right to approve all block group 
proposals for Census 2000. The Census Bureau will make an effort to 
reach agreement with local and tribal participants in the block group 
program, but cannot approve the use of block groups as submitted if 
they do not meet Census 2000 criteria. If necessary, the Census Bureau 
will revise block group boundaries where they do not meet the boundary 
and population size requirements.

B. Changes to the Criteria for Census 2000

    Most provisions of the block group criteria remain unchanged from 
those used in conjunction with the 1990 census, with the few exceptions 
summarized below:
    1. For 1990 and previous decennial censuses, the Census Bureau 
delineated the block groups in BNAs on the basis of the number of 
housing units rather than population. For Census 2000, the Census 
Bureau is merging the census tract and BNA programs to create a single 
census tract program, and the size criteria for all block groups will 
be on the basis of population rather than the number of housing units.
    2. For Census 2000, the Census Bureau is increasing the number of 
governmental units that have boundaries acceptable to use as block 
group boundaries. The added areas are: all MCDs in Indiana and selected 
MCDs in Illinois, Iowa, Kansas, Michigan, Minnesota, Missouri, 
Nebraska, North Dakota, South Dakota, and Wisconsin; the MCD-county and 
island areas of American Samoa; and villages in New York.
    3. The Census Bureau now allows officials of federally recognized

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American Indian reservations to establish block groups that cross state 
or county boundaries. While the Census Bureau will publish data for 
each state-county-census tract-block group part, it also plans to 
provide summed data for all block groups that are located within a 
federally recognized American Indian reservation and that cross state 
or county boundaries.

Definitions of Key Terms

    Alaska Native Regional Corporation (ANRC)--A corporate entity 
established under the Alaska Native Claims Settlement Act of 1972, 
Public Law 92-203, as amended by Public Law 92-204, to conduct both the 
business and nonprofit affairs of Alaska Natives. Twelve ANRCs cover 
the entire State of Alaska except for the Annette Islands Reserve.
    Alaska Native village statistical area (ANVSA)--A statistical 
entity containing the densely settled extent of an Alaska Native 
village that constitutes an association, band, clan, community, group, 
tribe, or village recognized pursuant to the Alaska Native Claims 
Settlement Act of 1972, Public Law 92-203, as amended by Public Law 92-
204.
    American Indian reservation (AIR)--A federally recognized American 
Indian entity with boundaries established by treaty, statute, and/or 
executive or court order and over which American Indians have 
governmental jurisdiction. Along with reservation, designations such as 
colonies, communities, pueblos, rancherias, and reserves apply to AIRs.
    Block numbering area (BNA)--A small-area, statistical geographic 
division of a county or statistically equivalent area delineated in 
1990 instead of and generally geographically equivalent to a census 
tract. For Census 2000, the Census Bureau is merging the BNA program 
with the census tract program and converting all BNAs to census tracts.
    Census block--The smallest geographic entity for which the Census 
Bureau collects and tabulates decennial census information, bounded on 
all sides by visible and nonvisible features identified by the Census 
Bureau in computer files and on maps.
    Census tract--A small, relatively permanent statistical geographic 
subdivision of a county or statistically equivalent area defined for 
the tabulation of data. For Census 2000, the Census Bureau is replacing 
BNAs with census tracts.
    Coastal water--Water bodies between territorial seas and inland 
water, the encompassing headlands being greater than 1 mile apart and 
less than 24 miles apart.
    Conjoint--A description of a boundary shared by two adjacent 
geographic areas.
    Contiguous--A description of geographic areas that are adjacent to 
one another, sharing either a common boundary or point.
    Great Lakes waters--Water area beyond one-mile-wide headland 
embayments located in any of the five Great Lakes: Erie, Huron, 
Michigan, Ontario, or Superior.
    Incorporated place--A type of governmental unit, sanctioned by 
state law as a city, town (except in New England, New York, and 
Wisconsin), village, or borough (except in Alaska and New York), having 
legally prescribed limits, powers, and functions.
    Inland water--Water bodies entirely surrounded by land or at the 
point where their opening to coastal waters, territorial seas, or the 
Great Lakes is less than one mile across.
    Minor civil division (MCD)--The primary governmental or 
administrative division of a county in 28 states, Puerto Rico, and the 
Island Areas having legal boundaries, names, and descriptions. MCDs 
represent many different types of legal entities with a wide variety of 
characteristics, powers, and functions depending on the state and type 
of MCD. In some states, some or all of the incorporated places also 
constitute MCDs.
    Nonvisible feature--A map feature that is not visible on the 
ground, such as a city or county boundary through space, a property 
line, a short line-of-sight extension of a road, or a point-to-point 
line of sight.
    Special place--A specific location requiring special enumeration 
procedures because the location includes people not in households, or 
the area includes special land use. Special places include facilities 
with resident population, such as correctional institutions, military 
installations, college campuses, workers' dormitories, hospitals, 
nursing homes, and group homes; and land-use areas such as national 
parks. A special place includes the entire facility, including 
nonresidential areas and staff housing units, as well as all group 
quarters population.
    Territorial seas--Water bodies not included under the rules for 
inland water, coastal water, or Great Lakes waters (see above).
    Visible feature--A map feature that one can see on the ground, such 
as a road, railroad track, above-ground transmission line, stream, 
shoreline, fence, sharply defined mountain ridge, or cliff. A 
nonstandard visible feature is a feature that may not be clearly 
defined on the ground (such as a ridge), may be seasonal (such as an 
intermittent stream), or may be relatively impermanent (such as a 
fence). The Census Bureau generally requests verification that 
nonstandard features pose no problem in their location during field 
work.

    Dated: November 25, 1997.
Martha Farnsworth Riche,
Director, Bureau of the Census.
[FR Doc. 98-544 Filed 1-8-98; 8:45 am]
BILLING CODE 3510-07-P