Mining Incidents

Portable 1: 23 MSHA citations Metal/Non-Metal

Diamond Lime, L.L.C. · Surface
Controlled by Leroy W Johnson
Nelson, Nuckolls County, NE  ·  Intermittent
MSHA Mine ID: 2501272

Portable 1 has $4K in proposed MSHA penalties and $755 outstanding across 0 contested dockets, plus health sampling and the full incident record.

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Fatalities
0
Total incidents
0
Years on record
Latest incident
Compliance record
MSHA citations since 2010
23
citations
5
significant & substantial
$3,907
proposed penalties
$3,152
paid to date
81% of proposed penalties paid to date, a $755 gap.
Source: MSHA violations data, updated weekly.
Inspection activity
MSHA inspections since 2010
16
inspections on record
165
inspection hours
n/a
citations per 100 inspection hours
This rate is recorded citations divided by MSHA inspection hours, per 100 hours. It reflects inspection effort, not mine size or production.
Rate withheld: 165 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.

Portable 1 has $4K in proposed MSHA penalties and $755 outstanding across 0 contested dockets.

Penalty disposition
Differences between proposed and paid penalties reflect both settlements and conference reductions and amounts still owed. Outstanding is the balance currently owed.
$4K
proposed penalties
$4K
current assessed
$3K
paid to date
$755
outstanding
18 assessments are final orders; 0 contested dockets.
As of the most recent assessment on 2026-07-08.
Source: MSHA assessed-violations and conference/litigation data, updated weekly.
Violation severity profile
Shares are computed over citations that carry the MSHA gravity and negligence coding; a small share of records are uncoded.
21.7%
significant & substantial
8.7%
high negligence or reckless
21.7%
reasonably likely or greater
43.5%
permanently disabling or fatal if injury occurs
Negligence coding: 0.0% none, 4.3% low, 87.0% moderate, 8.7% high, 0.0% reckless.
Source: MSHA violations gravity and negligence coding, updated weekly.
Health sampling
A sample is a point in time compliance measurement, not an individual exposure history. These figures describe MSHA sampling records and do not establish causation or personal dose.

Metal and nonmetal contaminants (personal samples)
Many samples are screening measurements of substances with no applicable exposure limit; they are counted as samples but excluded from every over-limit figure. Over-limit shares use only limit-tested samples.

Last sampled: 2025-06-09
2
samples
0
limit-tested
Most sampled contaminants
  • Respirable dust, <.1mg2
Show the individual readings (2)
Date Contaminant Concentration Limit Conc / limit Occupation
2025-06-09 Respirable dust, <.1mg 0 Utility Man
2025-06-09 Respirable dust, <.1mg 0 Utility Man
Source: MSHA respirable dust, quartz, and noise sampling records, updated weekly. Metal/nonmetal contaminant figures come from MSHA's Personal Health Samples and Area Samples files (public record), updated weekly.
Ownership history
  1. Haddan Lime Products LLC 2010 to 2022
  2. Diamond Lime, L.L.C. 2022 to present
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year Employees
2026 2
2025 3
2024 3
2023 3
2022 3
2019 0
2018 2
2017 2
2016 2
2015 3
2014 2
2013 3
2012 3
2011 4
2010 3
Source: MSHA quarterly employment and production, updated weekly.

Portable 1 sits in Nuckolls County, Nebraska, where the Census mining category is 0.6% of county employment.

Local economic context
County figures come from the US Census Bureau's American Community Survey, 5-year pooled estimates, so the 2023 vintage covers 2019 through 2023. The Census category is 'mining, quarrying, and oil and gas extraction', which is broader than MSHA jurisdiction and includes oil and gas workers no mine employs. These figures describe the surrounding county, not this mine, and are not a factor in any specific incident.
Nuckolls County, Nebraska · Population 4,089
0.6%
Mining share of county employment
$70,201
Median household income
Source: US Census Bureau, American Community Survey 2023 5-year estimates.
Quarterly safety rates
Citations per million reported employee-hours. Rates begin in 2000, when MSHA's quarterly employment data starts; earlier incidents are counted but cannot be rate-adjusted. Quarters under 100,000 reported hours are greyed: too few hours for a stable rate.
Citations per million employee-hours, as reported to MSHA
Quarter Hours worked Citations S&S Per 1M hrs
2026 Q2 181 0 0 0.0
2026 Q1 198 0 0 0.0
2025 Q4 286 0 0 0.0
2025 Q3 183 0 0 0.0
2025 Q2 165 8 1 48484.8
2025 Q1 265 0 0 0.0
2024 Q4 195 0 0 0.0
2024 Q3 96 0 0 0.0
Show 40 earlier quarters
Quarter Hours worked Citations S&S Per 1M hrs
2024 Q1 975 0 0 0.0
2023 Q3 140 0 0 0.0
2023 Q2 134 0 0 0.0
2022 Q4 480 0 0 0.0
2022 Q3 295 0 0 0.0
2019 Q1 0 0 0
2018 Q4 340 0 0 0.0
2018 Q3 0 0 0
2018 Q2 0 0 0
2018 Q1 149 0 0 0.0
2017 Q4 64 0 0 0.0
2017 Q3 348 0 0 0.0
2017 Q2 0 0 0
2017 Q1 244 0 0 0.0
2016 Q4 0 0 0
2016 Q3 579 0 0 0.0
2016 Q2 26 0 0 0.0
2016 Q1 504 0 0 0.0
2015 Q4 80 0 0 0.0
2015 Q3 218 0 0 0.0
2015 Q2 0 0 0
2015 Q1 327 0 0 0.0
2014 Q4 114 0 0 0.0
2014 Q3 18 0 0 0.0
2014 Q2 3 0 0 0.0
2014 Q1 110 0 0 0.0
2013 Q4 199 0 0 0.0
2013 Q3 83 0 0 0.0
2013 Q2 15 0 0 0.0
2013 Q1 442 0 0 0.0
2012 Q4 43 0 0 0.0
2012 Q3 103 0 0 0.0
2012 Q2 206 0 0 0.0
2012 Q1 551 0 0 0.0
2011 Q4 934 0 0 0.0
2011 Q3 770 0 0 0.0
2011 Q2 197 0 0 0.0
2011 Q1 231 2 1 8658.0
2010 Q4 1,033 0 0 0.0
2010 Q3 94 4 1 42553.2

No reportable incidents on file.

MSHA has no recorded reportable accidents for this mine in the current dataset. New reports appear here within a week of being filed.