Nebraska Administrative Code › Topic - ENVIRONMENT AND ENERGY › Title 118 - GROUND WATER QUALITY STANDARDS AND USE CLASSIFICATION › Appendix A - GROUND WATER REMEDIAL ACTION PROTOCOL

Current through June 17, 2024
Procedures for Determining Needed Action for Point Source Ground Water
	 Pollution Events
If not already known, the Department will identify, if possible, the
	 source(s) of contamination and the responsible party (or parties). The
	 Department will notify the responsible party after the determination has been
	 made. A responsible party is to complete the following protocol in accordance
	 with Chapter 6, 001.
Part I. IMMEDIATE ACTION
Step 1. Initial Review
1) Perform an initial review to determine whether immediate action is
	 needed to eliminate the existence or likelihood of an imminent and substantial
	 threat to the public health and welfare or the environment or to mitigate the
	 significantly increasing difficulty of cleanup if action is delayed, and if so,
	 what actions are required. Base the review on as many of the items addressed in
	 Steps 6 and 7 as possible.
a) imminent - a short time span (i.e., less than 90 days)
b) substantial - a significant impact on the public or environment
	 (e.g., human illness or death, serious financial loss, severe ecological
	 damage)
c) significant - if action is delayed, cleanup costs increase by one or
	 two orders of magnitude
d) immediate actions - may include cleanup to at least an initial
	 level, stabilization or containment, monitoring, shutdown/ termination of
	 facility/activity, or any combination of measures. These actions are carried
	 out by the responsible party.
2) If the need for immediate action is apparent or if the need cannot
	 be readily determined, proceed to Step 2 and work in conjunction with
	 Department.
3) If no immediate action is necessary (e.g., due to the nature of the
	 pollution event developing over many years or moving slowly), proceed to Step
	 4.
Step 2. Implementation of Immediate Actions
1) Implement the immediate actions identified as required by Step 1 or
	 as determined necessary in consultation with the Department.
2) Proceed to Step 3 when the immediate actions have been
	 completed.
Step 3. Evaluation of Immediate Actions
1) Determine if immediate action has successfully eliminated the
	 imminent and substantial threat to the public health and welfare and the
	 environment or successfully mitigated any significant increase in difficulty of
	 cleanup associated with delayed action.
2) If the immediate action was unsuccessful, return to Steps 1 and
	 2.
3) If requirements were met, proceed to Step 4.
Step 4. No Immediate Threat Present
Immediate action is not now needed, but additional measures for
	 complete and permanent resolution of the problem may be required. Further
	 assessment is necessary to determine the need for any final remedial
	 action.
Part II. FINAL REMEDIAL ACTION
If at any time during the Part II assessment an immediate threat is
	 identified, return to Step 1 (Part I).
Step 5. Preliminary Assessment
1) Complete a preliminary assessment to evaluate the possible threat of
	 contamination to ground water. This assessment involve s a review of existing
	 information and require the collection of minimal or no field data. If it can
	 be determined from this preliminary assessment that there is no threat of
	 ground water contamination, proceed to Step 11. If ground water contamination
	 is possible or likely, proceed to Step 6.
Step 6. Initial Site Assessment
1) Before this or any subsequent assessments are started, contact the
	 Department to establish what information must be collected. In some cases where
	 ground water contamination is immediately evident, or where ground water could
	 not be used as drinking water, it may acceptable to combine Steps 6 and
	 7.
2) Complete an initial site assessment to determine if ground water has
	 been or is likely to be impacted by the point source. Work will be approved by
	 the Department prior to beginning the assessment. This assessment may involve
	 test holes to determine the proximity of contaminants to ground water. If this
	 initial assessment reveals that there is no threat of ground water
	 contamination, proceed to Step 11; otherwise proceed to Step 7 under the
	 direction of the Department.
Step 7. Detailed Site Assessment
1) Perform a detailed site assessment to determine the vertical and
	 horizontal extent of the ground water contamination and its impact or potential
	 impact to human health and/or the environment through examination of all
	 pertinent factors. Work will be approved by the Department prior to beginning
	 the investigation.
2) Provide the detailed site assessment to the Department. The
	 Department may, at any time, request additional information.
Step 8. Define Preliminary Cleanup Levels
A remedial action class (RAC) is defined for pollution events in three
	 types of ground water (or overlying soils) depending on the degree (or
	 potential) of use of the ground water as drinking water. The extent of remedial
	 action recommended will differ depending on the RAC of the contaminated (or
	 likely to be contaminated) ground water. The RAC assigned will be determined
	 from the condition of the ground water prior to the pollution event. The
	 Department will assign the RAC based on information submitted by the
	 responsible party in the detailed site assessment and other available
	 information.
RAC-1. This category includes ground waters of Class GA and the portion
	 of Class GB in a 500-foot radius (or greater, if determined necessary by the
	 Department) around all private drinking water supply wells. RAC-1 is
	 automatically assigned anytime a public or private drinking water supply well
	 has been polluted.
RAC-2. This category includes ground waters of Class GB (except for the
	 portion of Class GB placed in RAC-1) and Class GC(R).
RAC-3. This category includes, but is not limited to, ground waters of
	 Class GC (except for Class GC(R) which was placed in RAC-2).
The RAC categories are not intended to represent a ground water
	 classification system but rather a pollution event ranking scheme. It gives the
	 Department a method to determine the importance of remedial action based on the
	 use of the ground water. For instance RAC-1 is the category of highest rank; it
	 represents that ground water actually being used for drinking water and that
	 ground water intended to be used in a public drinking water supply. Therefore,
	 RAC-1 events will normally receive the most extensive remedial action
	 measures.
RAC-2 events involve ground water not now directly used as drinking
	 water but having a reasonable potential to be used in the future. The potential
	 for use exists if the ground water is located in a highly populated area or is
	 part of a regional, high-yielding aquifer or if otherwise justified. The RAC-2
	 category also includes ground water with prior contamination that may be easily
	 or cost-effectively treated to drinking water quality.
Pollution events will be of lowest importance, RAC-3, if the ground
	 water involved is not used, or likely to be used, as drinking water. Generally
	 remedial action measures will be least extensive for this category since the
	 future use of ground water for drinking is improbable. Justification for
	 assigning events to RAC-3 will be based on a combination of several different
	 reasons. One reason for unusability is poor natural quality which makes the
	 ground water unfit for human consumption. Insufficient yield is another reason
	 the ground water may not be used for drinking. A third reason is historical
	 contamination that occurred prior to the pollution event currently being
	 investigated (see NRS §
								81-1505(2)(d)).
	 This past contamination may have rendered ground water unsuitable for drinking
	 and uneconomical to treat. Past and present intensive land use is also a reason
	 why ground water could be unusable as drinking water. This includes areas of
	 concentrated industrial development or densely populated areas where ground
	 water is likely to be contaminated or will not be used as drinking
	 water.
The ranking of some events as RAC-3 does not mean there will be places
	 in the State where wholesale contamination of ground water will be allowed.
	 Departmental authority through its various programs to control practices or
	 discharges that may contaminate ground water will still be in effect. RAC-3
	 events will be given a lower priority and less staff effort by the Department
	 than RAC-1 or RAC-2 events.
RACs were developed primarily for use with the principal aquifer--the
	 ground water commonly used for drinking. They will also be adapted for use with
	 both deeper and perched ground water. When doing so, interconnections with
	 overlying or underlying ground water of different quality will be
	 considered.
Some contamination threats may occur in which the use potential of the
	 ground water would be RAC-1 or RAC-2, but the soil, geology, and other
	 site-specific characteristics are such that ground water contamination is
	 virtually impossible. After an appropriate assessment, the event may be
	 downgraded to RAC-3.
In every ground water contamination occurrence, certain minimum
	 requirements will be imposed upon the responsible party, depending on the RAC.
	 Cleanup of readily removable contaminants (e.g., free product) will be
	 required. Additional cleanup and/or mitigation may also be required. If
	 additional cleanup is not required, the remaining contaminated ground water
	 will be managed and monitored to prevent any further damage.
In RAC-2, cleanup of readily removable contaminants (e.g., free
	 product) will be required. If additional cleanup is not required, the remaining
	 contaminated ground water will be managed and monitored to prevent any further
	 damage.
In RAC-3, cleanup of readily removable contaminants (e.g., free
	 product) will be required. Monitoring may also be necessary.
In addition to the minimum requirements listed above, RAC-1 and RAC-2
	 events are potentially subject to additional cleanup requirements. No further
	 cleanup will be required for RAC-3 events based on drinking water usage. In
	 certain cases,
1) The Department will set a preliminary cleanup level for additional
	 cleanup required. in RAC-1 and RAC-2 events. The idealistic goal of the
	 Department for any ground water cleanup is restoration - returning the ground
	 water to its quality before contamination (background levels). Most (if not
	 all) of the time these levels are impractical, unattainable, and (in some
	 cases) unmeasurable. Therefore, the preliminary cleanup level will be based on
	 the level necessary to maintain a drinking water use, although a preliminary
	 cleanup level set at the background level may be considered in some cases. If a
	 Department or EPA ground water/drinking water standard exists for the
	 contaminant, it will be the level used. If there is no established standard,
	 EPA's Ambient Water Quality Criteria, Health Advisories, and other documents
	 will be used to set the preliminary cleanup level. The level will be set at the
	 concentration which is estimated to result in a 1 in a 1,000,000 (10-6) excess
	 cancer risk over a lifetime, at the concentration which is expected to result
	 in no adverse health effect for longer-term or lifetime exposure, or the
	 laboratory detection limit (if higher and within an acceptable range). If
	 appropriate EPA data is nonexistent, data found in the literature will be used
	 to determine the preliminary cleanup level. If sufficient information regarding
	 acceptable levels is not found, the preliminary cleanup level will be set at
	 background or the acceptable laboratory detection limit.
Sometimes the background level of a contaminant (as reported by the
	 responsible party and approved by the Department) may be higher than what would
	 be proposed as the preliminary cleanup level in the preceding paragraph. In
	 these situations the background level will be used as the preliminary cleanup
	 level.
In a few cases ground water cleanup based on drinking water use may not
	 be sufficient to maintain other beneficial uses. For these unusual instances,
	 preliminary cleanup levels will be based on the level needed to maintain the
	 uses other than drinking water. This may necessitate cleanup even in RAC-3
	 events. Although the ground water in RAC-3 areas is not used as drinking water,
	 it may serve other important uses (e.g., irrigation, industrial). It may also
	 be necessary to set cleanup levels which protect streams and lakes from a
	 contaminated ground water discharge that would violate surface water standards.
	 Finally, the proximity to RAC-1 or RAC-2 areas, the likelihood of slow but
	 eventual migration to these areas, and the cumulative effects of a series of
	 contamination events must be considered when setting the preliminary cleanup
	 level for RAC-3.
After receiving notification, either agree to the preliminary cleanup
	 level or propose an alternate level. If a different cleanup level is proposed,
	 it must be based on technological, economic, and/or risk analyses completed by
	 the responsible party.
a) The technological analysis will determine if technologies exist to
	 clean up the ground water to the preliminary cleanup level. If technologies do
	 exist, report the various methods, including the contribution of cleanup
	 processes which occur naturally. If cleanup to the preliminary level is not
	 technologically possible, report what level of cleanup is attainable. As part
	 of this analysis, the technological feasibility of various mitigative actions
	 (e.g., supplying new sources of water and point-of-use treatment) should be
	 investigated.
b) For an economic analysis, examine the economics of cleaning up to
	 the preliminary level. If it is impossible to reach the preliminary cleanup
	 level, report what level of cleanup is economically possible. Analyze the
	 economic feasibility of mitigation instead of cleanup as well.
c) A risk analysis may include other factors, information, or
	 evaluations not previously considered, to be based on the risk of the
	 contamination harming human health and/or the environment.
If cleanup to the preliminary level is not attainable based on the
	 foregoing analyses, report what portion of the ground water will remain
	 contaminated following a lesser degree of cleanup. Given the technological
	 considerations of cleanup, the appropriate calculations should be used in an
	 attempt to define the three-dimensional boundary of the contamination plume
	 under different remedial action scenarios (including no cleanup). The
	 contamination plume, in this case, is defined as ground water where the
	 concentrations of identified contaminants exceed their preliminary cleanup
	 levels. For every cleanup scenario assessed, the economic impacts are to be
	 defined. The relationship of the contaminated ground water boundary to existing
	 users and discharge points of ground water are to be described.
If submitting an alternative cleanup level, include any supporting
	 justification for an alternate cleanup level, a contamination maintenance
	 program, a mitigation plan, or combination. The Department will consider the
	 information contained in the justification on a case-by-case basis and
	 establish a proposed final cleanup level or action. The level may be the same
	 as the Department's preliminary cleanup level, the same as the proposed
	 alternate cleanup level, or some other level.
The Department's decision on the remedial action necessary, including
	 the proposed final cleanup level, will be placed on public notice. Any person
	 may submit written comments on the proposed action or may request a
	 hearing.
Following the comment period and any hearing, the Department will
	 notify the responsible party of the Department's final decision (including
	 changes made as a result of a hearing).
4) Develop a workplan for performance of the final remedial action. The
	 time frame for required action (including cleanup) will be the period of
	 potential exposure to the contamination in the absence of any remedial action
	 or 20 years, whichever is less. On a case-by-case basis, a longer period of
	 time may be allowed if adequately justified by the responsible party. The
	 workplan is subject to the Department's approval.
Step 9. Implementation and Review of Remedial
	 Actions
1) Obtain any other permits from the Department that may be required to
	 implement the workplan (e.g., UIC, NPDES).
2) Implement the remedial actions specified in the workplan.
3) Keep the Department apprised of cleanup efforts, and the Department
	 will periodically review the effectiveness of the remedial actions. If the
	 Department determines the long-term needs of protecting the public health and
	 welfare and the environment have not been, or are not being, satisfied or if
	 additional remedial action is necessary, the Department may require a return to
	 Steps 7 and 8.
4) A request may be made to modify the required final remedial action
	 during the implementation process. Any request must be accompanied by
	 additional justification as described in Step 8. The Department will review the
	 information, and if a change is appropriate, a public notice will be
	 issued.
Step 10. Final Review
A final review will be performed by the Department to determine the
	 need for any ongoing actions. These may include long-term monitoring to ensure
	 cleanup levels are stabilized and maintained, periodic sampling of nearby
	 supply wells, maintenance of installed structures, and annual case review. If
	 acceptable cleanup levels were never reached, ongoing monitoring or maintenance
	 may be necessary to ensure other ground water does not become
	 contaminated.
1) Continue any ongoing actions determined to be necessary by the
	 Department until ground water contamination is no longer a concern.
Step 11. Situation of No Threat to Ground Water
	 Quality
The situation does not pose a threat to ground water quality. However,
	 if other health, safety, or environmental concerns exist, they should be
	 addressed by the appropriate Departmental procedures.
Click here to
	 view