Attachment_A.pdf

Mechanical Integrity Test Plan South Beaches Regional WWTP

Deep Injection Well System

UIC Permit No. 0185898-005-UO/1M

Facility ID 16327

Brevard County Utility Services

2725 Judge Fran Jamieson Way

A-213

Viera, FL 32940

July 2024

ATTACHMENT A

South Beaches Regional Wastewater Treatment

Plant Deep Injection Well System

Introduction and Background The Brevard County Utility Services Department (County) is planning on performing mechanical integrity testing of injection well IW-1 located at the South Beaches Regional Wastewater Treatment

Plant (WWTP). The South Beaches Regional WWTP is located at 2800 South A1A, Melbourne Beach, Florida 32951. A site location map and site plan schematic are presented on Figures 1 and 2, respectively.

The current permitted capacity of IW-1 is 12.73 million gallons per day (mgd) at a velocity of 10.0 feet per second (fps). On July 8, 2020, the County submitted to FDEP UIC an application to renew their injection well system operations permit, No. 0185898-004-UO/1M. However, since the County was in the process of rerating IW-1 to a higher capacity and in correspondence dated November 4, 2021, FDEP gave the County the option to delay the permit issuance until the results of the rerate test would be available. The re-rating of the deep injection well was completed in February 2022, rerating the injection well from 9.0 mgd to 12.73 mgd and was accepted by FDEP in February 2022. Then, FDEP issued the current operating permit for the facility on November 16, 2022, which included the rerated capacity of 12.73 mgd. Also, the injection well system operating permit requires that internal mechanical integrity be demonstrated by March 8, 2027, for IW-1.

The following tests are required in accordance with specific condition I B(g) of the previously mentioned operating permit:

A video survey as required by Chapter 62-528.425(1) (d) of the Florida Administrative Code

(FAC);

A pressure test as required by Chapter 62-528.300(6) (b) 2 FAC; and

A temperature log and radioactive tracer survey (RTS) as required by Chapter 62-528.300(6)

(c) FAC.

Description of Injection Well System

The South Beaches WWTP injection well system currently consists of one operational injection well located on the site property. As described above, IW-1 is currently permitted to inject up to an average annual daily flow rate of 12.73 million gallons per day (MGD). The injection well is used to dispose of secondary treated effluent.

Figure 1-1 South Beaches Regional WWTP

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Esri Community Maps Contributors, Brevard County, FDEP, © OpenStreetMap, Microsoft, Esri, TomTom, Garmin, SafeGraph, GeoTechnologies, Inc, METI/NASA, USGS, EPA, NPS, US Census Bureau, USDA, USFWS, State of Florida, Maxar, Microsoft

Wastewater Treatment Facilities

.Property BoundaryReplacement Deep Zone Monitoring WellFormer Deep Zone Monitoring Well (abandoned)

Shallow Zone Monitoring WellInjection Well

IW-1

MW-3

MW-1

South Beaches Regional WWTP Deep Injection Well System

Figure 3 depicts the construction detail for IW-1. The injection well is cased with a nominal 20-inch diameter 0.5-inch wall steel casing extending to a depth of 2,080 feet below pad level (bpl). The open hole construction of IW-1 extends to a depth of approximately 2,916 feet bpl. The calculated volume for IW-1 is approximately 5,919 cubic feet or 44,282 gallons from pad level to bottom of the well.

In addition to the injection well located within the South Beaches WWTP injection well system, there is an upper zone monitor well, designated as MW-1, and lower zone monitor well, designated as MW-

3. Figure 4 depicts the construction details of the monitor wells. The upper zone monitoring zone

(MW-1) is between 300 and 350 feet bpl. The lower zone monitor well monitors the interval just above the base of the Underground Source of Drinking Water (USDW) between 1,200 and 1,300 feet bpl.

Test procedures and a description of the test to be completed for IW-1 are presented in the following sections.

General Procedures for Mechanical Integrity Testing Mechanical integrity testing of IW-1 will be performed to demonstrate that the integrity of the well has not been compromised, there are no leaks in the final injection casing, and that there are no channels or fractures around the bottom of final injection casing that will permit injected effluent to migrate upward through the lowermost confining sequence below the base of the USDW.

Performance of the MIT will be closely coordinated with the County since emergency effluent disposal to the Indian River Lagoon (IRL) may be required during these activities. The Domestic Wastewater

Facility Permit for the WWTP (FL0040622) allows for a permitted discharge of 8.0 MGD over five days to the IRL every five years during performance of an MIT. To minimize discharge to the IRL, the

County will plan to operate reuse to the maximum capacity and utilize on-site storage at the South

Beaches Regional WWTP. The County will coordinate with the Florida Department of Environmental

Protection (FDEP) with respect to the date of discharging to the IRL.

Pressure testing, temperature logging, and video surveying the inside of the injection casing will evaluate the possibility of leaks in the injection casing. The possibility of upward migration through channels or fractures around the bottom of the injection casing will be evaluated by static temperature surveys and RTSs. A designated FDEP representative will be notified at least 72 hours prior to the initiation of all tests. The tests will be performed during normal working hours (8 a.m. to

5 p.m., Monday through Friday) unless the FDEP representative agrees to an alternate schedule. The

Figure 3 Construction Details of Injection Well IW-1

Figure 7 SBRWWTP IW-1 Repermitting

Construction Details of the Shallow (MW-1) and Intermediate (MW-3) Monitor Wells

INTERMEDIATE MONITOR WELL (MW-3)

SOURCE: GERAGHTY & MILLER, INC.

Construction Details for the Shallow (MW-1) and Intermediate (MW-3) Monitor Wells

Figure 4 Construction Details for the Shallow (MW-1) and Intermediate (MW-3) Monitor Wells

C:\_Projects\297221_SouthBeachesDIW\MIT_Plan_2025\Doc & Figs\Edits\South Beaches DIW MIT Plan 07012024.docx engineer will coordinate the testing schedule with FDEP. The following general procedures will occur during the mechanical integrity test:

Effluent will be used to flush the injection well after tracer release. Potable water will be used for the low flow rate dynamic portions of the RTS. Fresh water lines used for testing will be fitted with suitable check valves to prevent backflow.

A well survey will be performed through a suitable stripper head on the existing wellhead to prevent the release of effluent. Testing will be performed on a concrete well pad that is curbed and sloped to prevent the release of effluent. The containing curbing around the well pad allows the drainage of rainwater and will be plugged with some form of temporary enclosure prior to testing.

All flow and pressure measuring devices will be calibrated within the past six months prior to the start of the MIT field activities. All geophysical logging equipment will be calibrated as per the manufacturer’s recommendations.

All work shall be performed by a qualified well contractor with the test sequence being as follows: video survey, casing pressure test, temperature log, background gamma log, and RTS.

However, sequence is subject to change for operational needs and coordination of well drilling contractor, but FDEP will be notified in advance.

Video Survey

The video survey is anticipated to be conducted prior to the casing pressure test and RTS to assess the condition of the well. This survey will be used to visually evaluate the cased portion of injection well final casing and the open hole injection zone.

Prior to performing the color video survey on the injection casing, the injection well will be flushed with three well volumes of clear water, which is approximately 100,000 gallons. During the last video survey of IW-1 (March 7, 2022), video survey was obtained to a depth of 2,221 feet bpl due to the presence of bridging with large rock fragments, which blocked the borehole and prevented passage of the surveying equipment.

After the well has been flushed, the recording of the survey will begin at the top of the casing, with the reference datum for the survey being pad level. The video camera will be equipped with sufficient cable to enable the entire well to be surveyed and will have sufficient lighting to ensure that a good quality picture of the well is obtained. The video camera will be centralized in the casing and borehole during the survey and be equipped with an accurate depth counter. The depth counter will be calibrated at the reference datum and the bottom of the casing. The video survey will be conducted over the entire length of the well from land surface to the bottom of the injection zone.

The video camera will be equipped with a wide-angle lens and have the capability to obtain both horizontal and vertical views of the well interior. In addition, the camera will be equipped with a variable intensity light to illuminate the well interior. The survey will be conducted to the satisfaction of the engineer, and in the presence of the engineer and FDEP representative, if they wish to witness the survey.

C:\_Projects\297221_SouthBeachesDIW\MIT_Plan_2025\Doc & Figs\Edits\South Beaches DIW MIT Plan 07012024.docx

The video from the survey will be reviewed by the engineer to determine the condition of casing interior and the open hole. Any visual imperfections in the casing or a plugged interval of the injection zone will be noted. The decision to clean the casing wall or not to clean the casing wall will be made at this time. If the casing wall requires cleaning, the video survey will be performed again.

Pressure Testing

To demonstrate that there are no leaks in the final injection casing, IW-1will be pressure tested under the criteria specified in Section 62-528.300(6), FAC. In preparation for the pressure test, weighted material, such as salt, will be used to control flow in the subject well. Prior to pressure testing the entire length of the casing will be brushed with an appropriately sized steel brush to remove scale and bacteria growth. This will aid in providing a satisfactory seal for the packer seat interval.

A single element hydraulic packer (Baker, Tam International, or equivalent) with a rubber sleeve will be installed in the injection casing to perform the casing pressure test. The packer will be of a diameter appropriate for the size of the well casing to be tested. The packer will be conveyed via drill pipe to the proposed setting depth at the bottom of the casing. The proposed setting depth will be within 20 feet from the bottom of the injection casing. The packer element will be pressurized adequately to set it firmly in the casing. Once the packer is set, a temporary wellhead device will be put on the injection casing to allow for pressurization of the casing.

Section 62-528.300(6)(e), FAC, requires a pressure test of a minimum one-hour duration, at a pressure of at least 1.5 times the expected operational pressure of the well, with less than a 5 percent change. During pressure testing of the well, test pressure will be increased to 160 psi, which is more than 1.5 times the maximum permitted injection pressure of the well. The pressure should not vary by

± 8.0 psi change from the initial test pressure during the one-hour testing period. The resolution of the pressure gauge face will be graduated in one (1) psi increments, will range from 0 to up to a maximum of 300 psi, and will be accurate to ± 0.5 percent. A copy of the pressure gauge calibration certifications must be submitted to the engineer and FDEP representative prior to the beginning of the test. The certifications should include the date and place of the certification. It will be required that the pressure gauges be calibrated within the past six months of the test date.

After filling the casing above the packer with water, the specified pressure will be achieved by using a high-pressure water pump and will be held for one hour. Calibrated pressure gauges will be connected to the injection well wellhead so that readings may be recorded from the casing interior and the packer element. Pressure readings will be collected at five-minute intervals for a period of one hour during the pressure test and will be witnessed by the engineer and FDEP representative.

If the results from the pressure test indicate a pressure fluctuation of less than 5 percent (8.0 psi) over the one-hour test period, this phase of testing is completed. However, if a leak is detected by the pressure test, the contingency plan will be to first check that the packer is functioning properly. If it is determined that the packer is fully operational, the packer will be moved up in 200-foot increments, reset, and the packer test performed until no leak is detected. Suspected leakage will be confirmed more precisely via the video survey and temperature log.

At the end of the test, the pressure held on the casing will be released. The total volume released will be measured to determine that an adequate amount of water was used to pressurize the casing. The temporary wellhead shall be disassembled, the packer tripped out of the well, and the injection

C:\_Projects\297221_SouthBeachesDIW\MIT_Plan_2025\Doc & Figs\Edits\South Beaches DIW MIT Plan 07012024.docx wellhead reassembled. After the pressure test is completed, the weighted material will be flushed from the well and properly disposed of. It is anticipated that one casing volume of effluent should be adequate to remove the weighted material and establish buoyancy similar to operating conditions.

One casing volume is approximately 33,000 gallons for the well.

Temperature Log The temperature log will assist in determining the condition of the injection casing and open hole of the well. This log can assist in determining casing integrity by identifying temperature anomalies that can occur from flow through casing breaches.

The existing wellhead will be used to perform the temperature survey on the well. Stripper heads, pack-offs, and valve subassemblies will be required to control flow during logging. This survey will be conducted under static conditions prior to injecting fluids for the performance of the RTS. The well will remain static for a minimum of 12 hours prior to temperature logging. The log recording will begin at land surface and end at the bottom of the injection zone, with the reference datum for the logs at the well pad.

The temperature tool will be calibrated prior to entering the well and capable of accurately measuring temperatures ranging from 50 to 150 degrees Fahrenheit. The temperature log presentation will include both gradient and differential temperature measurements.

Radioactive Tracer Survey (RTS)

Equipment Requirements

The existing wellhead assembly on IW-1 will be used to perform the radioactive tracer surveys. The wireline and tool string for the surveys will be run through a riser pipe of sufficient length and diameter to accommodate the tool string. The riser pipe will be equipped with a pack-off seal and stripper for the wireline and a subassembly with a valved fitting of sufficient size to allow injection of effluent at rates required for testing. A pump capable of injecting at rates of up to 76 gpm against the system head conditions will be provided for the low-rate dynamic phases of the RTS. The injection rate will be measured by a calibrated in-line totalizing flow meter. The RTS will be performed within the bounds of the concrete well pad that is curbed and sloped to prevent spillage of effluent. The containing curbing around the well pad allows the drainage of rainwater and will be plugged with some form of temporary enclosure prior to testing. Potable water will be used during this low-rate test. A backflow preventor will be installed by the well drilling inspector to prevent effluent from backflowing into the potable water source.

A typical radioactive tracer tool assembly is shown on Figure 5. The upper and lower gamma ray detectors will be at least six feet above and below the tracer ejector port. The type of natural gamma ray detector that will be specified in the project contract documents will be the scintillator type. The radioactive isotope of Iodine (I-131) is proposed for use as the tracer. The tracer will be dated less than one half-life at the time of use. The tool assembly will be equipped with a casing collar locator

(CCL) to accurately determine the bottom of the casing.

Time will be recorded continuously during all surveys and will be included on the logging presentations. The precise injection times (moments of tracer injection) will be recorded by the tool.

Figure 5 Typical Radioactive Tracer Toolstring

The engineer and the geophysical logging contractor will record the precise injection times manually as a backup measure. The injection times will be recorded on the appropriate RTS log headers. The minimum level of calibration of the tracer injection time will be to the nearest + or - one (1) millisecond. The project contract documents will allow no lag time between injection and monitoring.

RTS Procedures

The RTS will be performed after the completion of the other phases of mechanical integrity testing for the well. Prior to the start of the RTS, the injection casing will be flushed with approximately 100,000 gallons of effluent to provide fluid buoyancy at the bottom of the casing. The survey will then be conducted in the well, according to the following steps.

1. Perform a background natural gamma ray log (baseline gamma ray survey) from the reference datum of pad level to the bottom of the injection zone, hole conditions permitting. The bottom of the injection zone for IW-1 is at 2,704 feet below pad level, however, due to the bridged rock fragments at 2,221 feet bpl, the extent of the logging will be limited to 2,221 feet bpl.

2. Locate the bottom of injection casing accurately with CCL with multiple logging passes.

3. Perform Initial Low-Rate Dynamic Radioactive Tracer Survey

a. Position the ejector port approximately five feet above the bottom of the final injection casing

(2,080 feet bpl). If staining persists, the logging tool will be raised in increments of five feet until staining is no longer detected.

b. Establish a 5.0 ft/min (79 gpm) flow of effluent in the well to minimize the immersion of the gamma ray detectors into the I-131 tracer. Eject 1.0 mci of the I-131 tracer. Hold tool stationary in position in time drive for one hour.

c. Cease injection, then log out of position upward 200 feet above the bottom of the casing.

Compare gamma log with background gamma log.

d. Flush with effluent at plant operating rate until the tracer has been displaced from the casing and staining has been minimized. Log after flush 200 feet above the bottom of the casing.

e. If no upward movement of the tracer is indicated by the gamma log comparisons, proceed to the second low-rate dynamic phase of the RTS.

f. If upward movement is indicated, then increase the upward logging interval immediately in step 3.d to track the tracer movement until it can no longer be identified. After there is no longer any detectable upward movement of the tracer during the initial low-rate dynamic test phase, proceed to second low-rate dynamic phase of the survey.

4. Perform Second Low Rate Dynamic RTS

a. Position the ejector port approximately five feet above the bottom of the final injection casing.

The contingency plan will be to raise the RTS tool an additional five feet above the bottom of the casing. If staining persists, the logging tool will be raised in increments of five feet until staining is no longer detected.

b. Establish a 5.0 ft/min. (79 gpm) flow of effluent in the well to minimize the immersion of tracer. Eject 1.0 mci of the I-131 tracer. Hold tool stationary in position in time drive for approximately one half-hour.

c. Cease injection, then log out of position to 200 feet above the bottom of the casing. Compare gamma ray log with background gamma ray log.

d. Flush with effluent at plant operating rate until the tracer has been displaced from the casing and staining has been minimized. Log after flushing at a depth of 200 feet above the bottom of the casing.

e. If no upward movement of the tracer is indicated by the natural gamma ray log comparisons, empty remaining tracer in the open hole below the casing and flush with effluent at plant operating rate.

f. If upward movement is indicated, then increase the upward logging interval in step 4.d.

immediately after the tracer passes the upper detector and track the tracer movement until it can no longer be identified. If necessary, repeat low rate dynamic RTS phase to confirm test results. After there is no longer any detectable upward movement of the tracer during the low-rate dynamic test phase, empty remaining tracer in the open hole and flush with effluent.

5. Perform final natural gamma ray log from bottom of open hole to land surface. Compare final gamma ray log with background gamma ray log.

6. Unforeseen field conditions and logging responses may require modification to the overall procedures of the RTS. Any field modifications will require the concurrence of the FDEP representative.

Upon completion of the RTS, the contractor will remove the stripper head, tool packoff, subassemblies, and return the injection well to operational service. The pump required to perform the RTS will be removed at this point. The wellhead has adequate valving to allow for the installation and removal of this equipment while controlling flow and protecting against the spillage of effluent. Any spillage, should it occur, will be contained on the well pad.

Summary Report A report summarizing the results of the mechanical integrity test elements will be prepared and sealed by the engineer of record. This report will be submitted to FDEP with the first regular quarterly report after the completion of testing. The report will contain all data collected during the testing and monitoring phases, equipment calibrations, interpretations, five-year trend analysis on water quality and operating parameters, conclusions and recommendations. This report will be sent to the Aquifer

Protection Program in Tallahassee and a copy of the cover letter for the MIT results will be sent to the

US Environmental Protection Agency, region 4, underground injection control program in Atlanta, GA.