The following items shall be included in the operation plan
for each phosphogypsum stack system and shall be approved by an engineer
experienced in the construction and operation of phosphogypsum stacks:
(1) The method used to raise and operate the
stack.
(2) A description of the
source and consistency of gypsum used in constructing the gypsum dikes and the
method used for shaping and/or rolling the gypsum.
(3) The overall average exterior slope for
raising the phosphogypsum stack and the maximum design height of the
stack.
(4) The procedures used to
assure that pipes used to transport phosphogypsum to the phosphogypsum stack
systems and to return process water to the phosphate fertilizer production
facilities are operated and maintained in a safe manner.
(5) The procedures used to decant process
water from the top of the phosphogypsum stack.
(6) The location of pumps, spillways, and
staff gauges.
(7) Provisions that
address emergency measures to be taken in the event of mechanical failure of a
pump or in the event of a power failure for any portion of a phosphogypsum
stack system that relies on pumps or power to operate monitoring equipment or
to transfer process water and/or rainfall-runoff from low areas to the main
cooling pond. Such emergency provisions may include:
(a) Back-up power (e.g., on-site power;
diesel generator, etc.) and/or back-up pump which would be activated in the
event of electrical or mechanical failure, or
(b) Sufficient surge storage capacity or
emergency surge capacity within the conveyance system to contain the process
water stream(s), if applicable, as well as runoff from a storm event generating
12 inches of rainfall in 24 hours, or
(c) Increased inspection frequencies or
continuous monitoring (e.g., remote video camera or automatic water level
control device tied to a warning system) to provide early warning of an
imminent spill prior to its occurrence; and an emergency action plan that would
be undertaken to prevent or contain an accidental spill.
(8) A site-specific water management plan
updated annually to reflect changes in process watershed area, storm surge, and
projected water balances. The updated plan, consistent with water quality based
effluent limits applicable to the facility, shall be submitted to the
department by February 1 of each year.
(a)
Each plan shall specify, at a minimum, a set of specific actions, including
minimum process water consumption and transfer rates, that are put into motion
when certain "triggers" are exceeded in the cooling/surge pond system. The plan
shall specify additional actions that shall be implemented prior to exceeding
such triggers in the cooling/surge pond system, where such actions are
determined to be necessary based on water balance model results for the
rainfall scenarios described in subsection (9), below. For facilities with
approval to store process water in an AHP or RHP, such additional actions
shall, at a minimum, specify the operational conditions for transferring to or
removing process water from each authorized AHP, whether lined or unlined, or
any RHP. Each trigger shall correspond to the event or system storage volume or
operating water level(s) needed to contain the storm surge (or a fraction of
the storm surge) in the system from a specific design storm (e.g., 12 inches in
24 hours, or the 25-year/24-hour event). If provisions are made to contain the
direct rainfall quantity from a storm event generating 12 inches of rainfall in
24 hours in the settling compartments atop the phosphogypsum stack, then the
top area of the stack need not be considered in calculating the process
watershed of the cooling/surge pond system and corresponding storm surge
capacity.
1. The trigger levels in the
cooling/surge pond system shall include:
a.
The "action plan" trigger corresponding to the event storage volume or
operating water level(s) required to contain the rainfall quantity from a storm
event generating 12 inches of rainfall in 24 hours. When this level is exceeded
for 72 consecutive hours, the owner of the system shall notify the department
in conjunction with the weekly reporting required under paragraph (c), of this
subsection, and present for the department's review a site specific action plan
(or refer the Department to a previously submitted site-specific action plan)
for process water inventory management and/or consumption.
b. The "may treat" trigger corresponding to
the event storage volume or operating water level(s) required to contain the
25-year/24-hour storm event. When this trigger is exceeded for 48 consecutive
hours, the owner of the system shall notify the department on the next working
day and begin implementing activities needed for activating any permitted
treatment station(s), or, alternatively, the owner shall undertake actions to
increase the available surge storage capacity within the process system which
could include reductions in the volume of water reporting to the process water
system, transfer of process water within the phosphogypsum stack system, or
transfer of process water to one or more AHPs or RHPs. Incorporation of process
water treatment and discharge as a specific action in the site-specific water
management plan at this level by facilities that have a department permit to
discharge is optional.
c. The "must
treat" trigger corresponding to the system storage volume or operating water
level(s) required to contain one half of the 25-year/24-hour storm event. When
this level is reached or exceeded, the owner of the system for which the
department has issued a discharge permit shall notify the department in
writing, within 24 hours. Whenever the "must treat" trigger is exceeded for 24
consecutive hours or more, the owner or operator of the system shall treat
process water for reuse or discharge in accordance with the facility's
site-specific water management plan.
2. For purposes of establishing the "action
plan" and "may treat" triggers, the portion of the storage capacity of a
department-approved AHP corresponding to that which would be available during a
24-hour period, through any combination of gravity flow and emergency measures
identified in the operation plan, shall be taken into account.
3. For facilities that are authorized to use
a department-approved RHP, the storage capacity of the RHP shall not be taken
into account in establishing the "action plan, " "may treat, " and "must treat"
triggers. However, use of an RHP may be part of a facility's site-specific
water management plan.
4. When
process water is to be moved into an AHP or RHP that does not contain process
water, the owner of the system shall notify the department, in advance when
feasible, but not later than one business day after transfer begins. Whenever
process water is stored in an RHP, the owner shall implement all measures
needed to consume, remove or treat the water from the RHP as soon as
practicable. When an AHP or RHP is emptied of process water, the owner of the
system shall notify the department within 7 days. An RHP is required to have
either a separate operation and contingency plan, or be included as part of a
single facility's operation and maintenance plan.
5. Whenever the "action plan, " "may treat, "
and "must treat" triggers are exceeded, the owner or operator of the system
shall implement the applicable specific actions in accordance with the
facility's site-specific water management plan. Where the plan specifies that
additional actions are to be implemented prior to exceeding the "action plan, "
"may treat, " and "must treat" triggers, the owner or operator of the system
shall implement such additional actions in accordance with the facility's
site-specific water management plan.
(b) Each facility's water management plan
shall be site-specific and shall be based on a water balance analysis performed
annually which considers the rainfall scenarios described in subsection (9),
below.
(c) Each facility must
maintain records for at least three years to identify the "trigger" levels.
This record should contain as a minimum a site-specific water balance summary
sheet which includes the following elements:
1. Water levels in each impoundment area,
2. Operating levels and trigger
levels of each impoundment area,
3.
Acreage of each impoundment area,
4. Acreage of watershed that contributes to
the impoundment area,
5. Available
storage capacity at the various operation levels, in inches of rainfall runoff
and acre feet,
6. Available event
and system storage, in inches of rainfall runoff and acre feet; and,
7. Available maximum potential storage, in
inches of rainfall runoff and acre feet, where determined in accordance with
subsection
62-672.870(1),
F.A.C.
Each facility shall provide the department the water balance
summary sheets at the following frequency:
a. Monthly by the 15th of each month when
water levels are below the "action plan" trigger. The summary sheet provided
shall contain the required information for the last day of the preceding
month.
b. Weekly on the Tuesday of
each week when the "action plan" trigger is exceeded. The summary sheet
provided shall contain the required information for the preceding
Friday.
c. Daily (except weekends
and holidays) when either the "may treat" or "must treat" triggers are
exceeded. The summary sheet provided shall contain the required information for
the preceding day.
Each facility shall also regularly monitor water levels as
required elsewhere by this rule as well as be able to demonstrate the water
levels and available event, system, and maximum potential storage capacity at
any time upon the request of the
department.
(d) For the purposes of this subsection,
information to be provided to the Department, including notifications required
herein, may be provided by facsimile, electronic mail, or other electronic
means where established by the department.
(9) The adequacy of the facility's
site-specific water management and action plans and emergency measures shall be
based on a five-year water balance analysis which shall be updated annually.
(a) The water balance analysis shall use
October 1 as the beginning date for the analysis. The analysis shall identify
the rates of all water inputs and outputs, any manufacturing production
changes, and changes in process watershed area considered in the analysis. A
third party engineer shall verify the accuracy of the analysis. A summary of
the analysis and the water balance analysis results shall be included in the
annual updated site-specific water management plan required in subsection (8),
above.
(b) The water balance
calculations shall be performed for the 5-year period using input rainfall
quantities which shall include either:
1. The
100-year September rainfall occurring during the 100-year Annual Rainfall as
defined herein, and multi-year rainfall events that have an equivalent
probability for not being exceeded during the 5-year period as that of the
100-year Annual Rainfall Event. Rainfall events other than the 100-year Annual
Rainfall shall be determined based on a long-term rainfall record from a
National Oceanic & Atmospheric Administration or equivalent weather station
in the vicinity of the facility. For the multi-year rainfall events other than
the 100-year annual rainfall, the annual rainfall quantities exceeding or less
than the long-term average annual rainfall shall be distributed amongst the
various months of the year in proportion to the normal monthly rainfalls
determined from the corresponding long-term record. For the 100-year annual
rainfall, the annual rainfall quantities exceeding or less than the long-term
average annual rainfall shall be distributed amongst the various months of the
year, other than the month for the 100-year September rainfall, in proportion
to the normal monthly rainfalls determined from the corresponding long-term
record; or
2. The input rainfall
quantities for each of the 5-year extreme rainfall scenario listed below:
|
Rainfall, inches
|
|
|
Year 1
|
Year 2
|
Year 3
|
Year 4
|
Year 5
|
Total
|
|
Scenario 1
|
76
|
60
|
56
|
56
|
52
|
300
|
|
Scenario 2
|
60
|
76
|
56
|
56
|
52
|
300
|
|
Scenario 3
|
56
|
60
|
76
|
56
|
52
|
300
|
|
Scenario 4
|
52
|
56
|
60
|
76
|
56
|
300
|
|
Scenario 5
|
52
|
56
|
56
|
60
|
76
|
300
|
For the 100-year annual rainfall and the multi-year rainfall
events, the annual rainfall quantities shall be distributed amongst the various
months of the year proportionally based on the values shown for each month as
listed below:
|
Portion of Annual Rainfall
Amount, Percent
|
|
|
100-Year Annual Rainfall
|
Other Multiyear Rainfall Events
|
|
January
|
3.2
|
4.5
|
|
February
|
3.7
|
5.2
|
|
March
|
4.1
|
5.8
|
|
April
|
3.4
|
4.8
|
|
May
|
5.7
|
8.0
|
|
June
|
15.2
|
14.8
|
|
July
|
15.9
|
15.4
|
|
August
|
14.5
|
14.1
|
|
September
|
24.8
|
13.9
|
|
October
|
4.1
|
5.8
|
|
November
|
2.5
|
3.5
|
|
December
|
2.9
|
4.2
|
(c) The water balance analysis for any
phosphogypsum stack system shall indicate whether the system storage will be
less than any of the following water balance targets:
1. 16.25 inches of rainfall run-off on June 1
of any year,
2. 12 inches of
rainfall run-off on October 1 of any year; and,
3. Water levels that exceed impoundment
maximum design levels at any time during a year.
If the water balance for any phosphogypsum stack system
indicates that system storage is less than the water balance targets, the owner
must provide reasonable assurance that additional process water consumption or
management items, not already included as outputs in the water balance
analysis, are readily available and capable of maintaining these water balance
targets. Use of available storage within an AHP or RHP, up to their maximum
design levels, may be used to provide this assurance. For a period not to
exceed three years following July 19, 2006, a company may utilize water levels
corresponding to maximum potential storage to provide reasonable assurance that
water balance targets will be met. In subsequent years, if the modeling results
of the annual water balance analysis provide reasonable assurance that the
water balance targets will be met utilizing only system storage on or after
June 1, 2011, a company may continue, at its discretion, to utilize water
levels corresponding to maximum potential storage for modeled periods prior to
June 1, 2011. Whenever a company relies on the use of maximum potential
storage, the water balance analysis must specify the assumptions that were used
to determine the temporary use of the design
freeboards.
(d) If
the water balance indicates that at any time during the five-year period that
process water levels, in conjunction with additional available process water
consumption or management items as described in paragraph (c), of this
subsection, will not meet the water balance targets, the owner must provide
additional process water consumption or management items, and submit an
alternatives plan and implementation schedule for department approval for the
additional consumption or management measures within 90 days of submittal of
the water balance analysis. The plan and schedule shall include, at a minimum,
the following elements:
1. A listing and
description of the additional process water consumption or management items to
be evaluated, including the identification of items that can be rapidly
implemented to achieve the water balance targets.
2. A listing of interim measures that can be
implemented to prevent an unpermitted release of process water in the event
that actual rainfall events contribute to process water levels exceeding
maximum design levels.
3. A
proposed schedule for the evaluation, selection, engineering, design, and
construction, installation or implementation for the items and interim measures
needed to increase water consumption, reduce inventories, or any combination of
such actions that will result in achievement of the water balance
targets.
4. Where such alternatives
or interim steps may include a new or increased discharge to surface waters of
the state, the evaluation of the new or increased discharge shall include:
a. Identification of any impaired waters and
parameters included on a verified list, determined in accordance with Chapter
62-303, F.A.C., for any water body or water body segment existing at or
downstream of the proposed new or increased discharge,
b. Identification of any Total Maximum Daily
Load, adopted in Chapter 62-304, F.A.C., for any water body or water body
segment existing at or downstream of the proposed new or increased discharge,
c. Preliminary estimates of any
proposed new or increased loading and concentrations, expressed on an annual
average basis, and a description of the expected frequency and duration of
discharge events that would be needed to meet the water balance targets and
terms of this paragraph for each of the identified impaired parameters,
d. A description of and estimated
quantity for potential pollutant loading offsets that may be available for any
proposed receiving water body or water body segments, if needed to implement
any alternative including a proposed new or increased discharge to impaired
surface waters of the state.
The department shall approve the plan upon a demonstration
that implementation of the plan will result in achievement of the water balance
targets. Upon receipt of an alternatives plan, the department shall approve or
deny the alternatives plan following the procedural steps outlined in Section
120.60, F.S. Any such additional
process water consumption capacity or other management items necessary to meet
the terms of this paragraph shall be installed in accordance with the approved
plan or within 18 months of receipt by the owner of all necessary permits or
other prior approvals whichever occurs
later.
(10) The site-specific water management plan
and action plans, based on an updated water balance analysis performed in
accordance with subsection (9), herein, for each phosphogypsum stack system and
complying with all of the provisions of this section, shall be submitted to the
department by no later than February 1, 2007 and annually
thereafter.
