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Project Details
Transportation & Government Services
Installation of 8 wells at the Miami Well Field
This project is part of Dayton Water’s PFAS Strategy. The objective is to ensure compliance with PFAS Maximum Contaminant Levels by increasing production at the Miami Well Field to convey raw water to the Ottawa Treatment Plant. Blending water to decrease PFAS concentrations will reduce O&M expenses associated with end-of-pipe treatment. These wells will increase the available supply from the Miami Well Field enabling Dayton to decrease the level of PFAS contamination in its finished water.
Organization Details
City of Dayton
101 West Third Street
Dayton, Ohio. 45402
Montgomery
Same
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Government
Organization Contact Details
Rosalind Bertolo
Special Projects Administrator
City of Dayton
937-333-3755
320 West Monument Avenue
Dayton, Ohio. 45402
Montgomery
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Location Details
Dayton
Montgomery
Ohio 10th
Financial Details
20000000
20000000
No source of a match is known at this time. The City of Dayton should not be responsible for the remediation of the PFAS contamination. Dayton did not cause the WPAFB contamination, which occurred outside of Dayton on property owned and controlled by the U.S. Government. The City has brought suit against the PFAS manufacturers as well as the Department of Defense in order to remediate these sites. It is inherently unfair to require the impoverished ratepayers of the City of Dayton to cover the cleanup of pollution that the City did not cause and that occurred outside of Dayton’s boundaries in areas where it had no control.
Construction or Capital
No
The City is working closely with OEPA regarding emerging contaminant funding. Funds allocated to OEPA through BIL may be available.
No
Within the next 6 months
OEPA Division of Environmental and Financial Assistance, State Revolving Loan Fund
Community Details
BACKGROUND

In 2016, the Environmental Protection Agency (EPA) introduced lower Health Advisory Levels (HAL) for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) at 70 ppts. The City had previously monitored for PFOA and PFOS during the Third Unregulated Contaminant Monitoring Rule (UCMR3) 2013-1015, with the results showing as non-detect at Ottawa and Miami Water Treatment Plant, as the detection limits were 20 and 40ppt respectively.

Upstream of the City’s water source Wright Patterson Airforce Base (WPAFB) detected PFAS during UCMR3 above the HAL. Under the advisement of the regulatory agency and out of an abundance of caution, the City took aggressive actions to preserve the source water and ensure its customers receive safe, high-quality drinking water. Measures included:

• Expanding the early warning monitoring well network.
• Monitoring at the treatment plants.
• Removing production wells from operational rotation.

The removal of production wells from operational rotation was viewed as a temporary solution while the City investigated more sustainable solutions, using the data gained from the increased monitoring schedules. Also, removing production wells decreased the water systems redundancy and increased operational costs as production wells are not rotated on their normal schedules.
In 2018, an updated analytical method was approved, lowering the quantifiable concentration numbers of PFOA and PFOS. Thus, the City started seeing detections in its Mad River Well Field and its Ottawa Water Treatment. The Mad River Well Field supplies water to the Ottawa Water Treatment Plant and the Miami Well Field supplies water to the Miami Water Treatment Plant. Currently, the water supplies are separate.

In June 2022, the EPA again lowered HAL for perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and introduced new HALS perfluorobutanesulfonic acid (PFBS), and GenX. The current City detections:
• PFOA 4 ppq (0.004ppt)
o Ottawa Water Treatment Plant 1.20 ppt (5/10/22)- 5.14 ppt (12/14/19)
o Miami Water Treatment Plant ND
• PFOS 20ppq (0.020ppt)
o Ottawa Water Treatment Plant 1.20 ppt (6/26/19)- 13.7 ppt (9/06/18)
o Miami Water Treatment Plant ND
• GenX 10ppt
o ND at Ottawa and Miami Water Treatment Points
• PFBS 2000 ppt
o ND at Ottawa and Miami Water Treatment Points

As previously stated, the City took temporary aggressive actions of removing production wells from operational rotation while waiting on the final guidance agency and developing a more permanent solution to manage PFAS contamination found in its water, based on data gathered from 2015 through the present.


2.01 Project Scope

This project is comprised of furnishing all materials, equipment, labor and ancillary work necessary for the drilling, construction and development of wells described in the following specifications. All work shall be completed in accordance with OEPA Water Well Standards.

The base bids shall cover drilling footage, materials, labor and development and other work in accordance with these specifications and the Proposal form. The estimated quantities in the proposal are to establish a project cost for the contract document and for bid comparison. The contractor will be paid based on the unit price for the actual number of lineal feet completed and accepted (measured to the nearest tenth of a foot) or hourly for the actual number of hours worked (measured to the nearest tenth of an hour.) Under the items of furnishing, drilling and installing the outer well casing, the contractor shall be paid only for the length of casing left in the ground after the completion of the job. The cost of setting the inner well casing shall be included in the drilling cost.

2.02 EIGHT (8) INCH TEST WELLS

Method of Construction

An eight-inch (8”) diameter test well shall be drilled at each site proposed and approved by the City of Dayton’s representative. If any particular site proves to be unsuitable for construction of a water supply well, a new site will be chosen and another test well shall be drilled.

The drilling of the test wells shall be done by the cable tool method or acceptable equal. Each test well shall be cased with new or used steel pipe not less than eight inch (8”) inside diameter and of sufficient thickness and strength to ensure completion of each test well to the depth required. Joints shall be made by welding and shall be watertight.

It is anticipated that a low-permeability bed of glacial material or bedrock will be encountered between one hundred and fifty (150) and two hundred and fifty (250) feet below ground surface. All test wells shall be carried to this depth unless otherwise directed by the City of Dayton. The payment for the 8” test wells shall be included in the unit price bid for Item 2, “Drilling 8” Test Wells”.

Water Sample

The contractor shall notify the City of Dayton when any test hole is open. If needed, the contractor shall screen the area of good formation and pump the well for at least four (4) hours so the City of Dayton can obtain a water sample. The City of Dayton’s representative shall take and deliver said water sample to the appropriate laboratory during normal working hours. Before proceeding with the installation of the production well, the City of Dayton may direct the contractor to wait until the laboratory analysis is completed. The payment for the water sample shall be included in the unit price bid for Item 2, “Drilling 8” Test Wells”.

Soil Samples

During drilling, representative samples shall be taken at five-foot intervals and at significant changes in the character of the formation. The samples shall be stored in glass containers (one-quart volume) with screw-on lids and shall be plainly and suitably labeled to show the well number, the depth from which the sample was taken and the date of collection. The samples shall be delivered to the City of Dayton. The contractor shall prepare a typewritten log of the geology of each test well during the drilling period and shall furnish three (3) copies to the City of Dayton upon completion of each test well.

Subsequently, the contractor shall pull the casing and screen and the casing and screen shall remain the property of the contractor. The payment for the soil samples shall be included in the unit price bid for Item 2, “Drilling 8” Test Wells”.

Sieve Analysis

The contractor shall perform a standard sieve analysis on the representative samples of materials collected from the depths relating to the placement of the screen. In said area at least one analysis shall be performed for every five- (5) foot of depth or as formation changes substantially, whichever is of greater frequency. A copy of the sieve analysis including a table and graph of the results shall be delivered to the City of Dayton. The contractor shall recommend appropriate screen slot size, screen length and design. The City of Dayton’s representative shall make the final decision for these parameters.

The payment for the standard sieve analysis shall be included in the unit price bid for Item 2, “Drilling 8” Test Wells”. Any additional sieve analysis, if required shall be included in the unit price bid for Item 3, “Additional Sieve Analysis, as Required”.


2.03 40” X 26” GRAVEL WALL WELLS

Method of Construction

The contractor shall use only the reverse circulation rotary method of construction. If proposing to use any other method(s) in conjunction with the reverse circulation rotary method, the contractor shall obtain prior approval of the City of Dayton’s representative.

In the reverse circulation rotary method, the forty-inch (40”) casing shall be sunk to the desired level below grade and grouted with concrete. The forty-inch (40”) casing shall be sunk to within five (5) to ten (10) feet above the start of good formation or as directed by the City of Dayton’s representative. A thirty-eight (38) inch hole shall be drilled to the level at which the bottom of the screen shall be set. After the hole is thoroughly cleaned to the bottom, the casing and screen, with closed bottom (welded stainless plate), shall be set in the forty-inch (40”) casing and the thirty-eight (38) inch open hole and then to the top of the screen and shall extend from the top of the screen to ground level. Graded silica gravel shall be placed between the screen and the forty-inch (40”) casing and the open hole. The silica gravel must not be less than ninety-five percent (95%) pure with a uniformity coefficient of 2.0 or less.

Before the gravel pack is placed, the contractor shall place a three-inch (3”) stainless steel screen in the annular space between the natural formation and the twenty six-inch (26”) screen the same length and slot size as the twenty six-inch (26”) screen. The contractor shall then extend the three inch (3”) steel pipe to the surface. The payment for the three-inch stainless steel screen shall be included in the unit price bid for Item 8, “Drilling & Installing 26” Inner Casing & Screen”.

The contractor shall furnish and install a four-inch (4”) steel filler pipe for gravel pack replenishment. The payment for the four-inch steel filler pipe shall be included in the unit price bid for Item 8, “Drilling & Installing 26” Inner Casing & Screen”.

Contractor shall furnish, but not install, 3-inch (3”) and 4-inch (4”) steel caps for the three-inch pipe and 4-inch filler pipe, Morrison Manhole 7”-10” 418 XA-0500AM, or approved equal. The payment for steel caps shall be included in the unit price bid for Item 8, “Drilling & Installing 26” Inner Casing & Screen”.

Final gravel level shall be determined by the City of Dayton, but will be no less than two feet (2’) below ground level. With the reverse circulation rotary method, the contractor shall provide portable mud pits. Mud additives such as Revert or Bentonite shall not be used in the drilling process. Work casings larger than forty-inch (40”) in diameter may be used and recovered by the contractor. The payment for the gravel pack is included in the unit price bid for Item 8, “Drilling & Installing 26” Inner Casing & Screen”.

Depth of Well

For bid purposes, it is expected that the well will be 140 deep. However, the exact depth will be determined by the City of Dayton’s representative from the test drilling.

Casing

The outside diameter of the inner well casing shall be twenty-six inches (26”). The outside diameter of the permanent casing shall be forty inches (40”). Work casings, if needed, shall be of adequate size and design for the use intended. The forty-inch (40”) casing shall be fabricated from new steel pipe having a minimum wall thickness of 0.500 inch. It shall conform to the requirements of Specification C200 of the American Water Works Association. Joints shall be made by welding and shall be watertight. The twenty-six inch (26”) casing shall be fabricated from new steel pipe having a minimum wall thickness of 0.500 inch and shall conform in all other respects to the forty-inch (40”) casing. At least four (4) feet of twenty-six inch (26”) casing shall remain above ground. At least two (2) feet of forty-inch (40”) casing shall remain above ground. If additional lengths are needed, the City of Dayton will notify the contractor before the well is accepted. The payment for the casing shall be included in the unit price bid for Item 4, “Furnishing 40” Well Casing” and Item 6, “Furnishing 26” Well Casing”.


Well Screen

The well screen furnished by the contractor shall be made of type 304 stainless steel. The screen shall be standard manufactured type as hereinafter described, and all fittings, shoes or other appurtenances shall be of standard weight, dimensions and design and made of the same materials as regularly furnished by the manufacturer for the type and size of screen furnished.

The screen shall not be less than twenty-six inch (26”) outside diameter. The screen shall be forty feet (40’) to seventy feet (70’) long as required. The screen shall be of the wire-wound welded type with vertical supporting bars as manufactured by US Filter/Johnson, Inc or approved equal. The contractor shall state in the bid the type of screen they propose to furnish. The payment for the screen shall be included in the unit price bid for Item 7, “Furnishing 26” Well Screen”.

It is intended that the width of the screen slot openings shall be such that the well can be developed to its maximum efficiency. The widths of slot openings decided upon shall be subject to the approval of the City of Dayton’s representative.

Before the gravel pack is placed, the contractor shall place a three-inch (3”) stainless steel screen in the annular space between the natural formation and the twenty six-inch (26”) screen the same length and slot size as the twenty six-inch (26”) screen. The contractor shall then extend the three inch (3”) steel pipe to the surface.

Equipment

The Contractor shall use a reverse circulation method or approved equal to install the well. Water for drilling will be made available to the Contractor by the City of Dayton. The Contractor shall use no fluid additives to increase the viscosity of the drilling fluid. Alternate methods are subject to prior approval by the City of Dayton since it is imperative that formation collapse, agitation and material removal be achieved for the success of this well installation program.

Vertical Alignment and Plumbness

The well shall be constructed round, true to line and shall not depart from the vertical more than twelve inches per 100 feet depth. If doubt exists as to the departure from the vertical, the contractor may be required by the City of Dayton to furnish equipment and test the plumbness of the well at no extra cost to the City of Dayton. The well will not be accepted and will be properly abandoned at the expense of the contractor if the straightness or vertical alignment is unsatisfactory to the extent that it interferes with the installation of pump intended for the well.

2.04 Well Development

The Contractor shall develop the well using a surging tool. This device shall be operated in conjunction with an air compressor rated at 600 cfm minimum. The surging tool shall be operated through the entire length of the well screen. This equipment shall consist of either a double action hydro-pneumatic tool or a twin disc surge block on the end of six-inch (6”) surge pipe. The Contractor must demonstrate to the City of Dayton that they have equipment capable of doing this type of well development.

The surging process shall continue until the discharge from the well is clear of sediment. At that time, the contractor will notify the City of Dayton, who will look at the discharge and make the final decision to either finish or continue surging. For the purposes of this bid, the Contractor shall assume a cleaning rate of two (2) feet per hour. The base bid shall include only actual surging time and shall not include set up, etc. The payment for the well development and set up shall be included in the unit price bid for Item 9, “Developing By Surge Block & Pumping 40” X 26” Well”.

Well Testing

The Contractor shall supply and install a test pump complete with power, discharge hoses and orifice. The pump shall be capable of at least 3,150 gpm output. The well shall be pumped for a total of 24 hours without interruption. The static water level shall be measured and recorded 30 minutes before starting. The test shall be a combination step draw-down/constant rate test. The testing will be in accordance with the following general guidelines, see OEPA Water Well Standards for complete requirements. The payment for the test pumping shall be included in the unit price bid for Item 10, “Test Pumping 40” X 26” Well at 3,150 GPM”.

The Contractor shall perform a four (4) step test. The rates shall commence at about 500 gpm and increase incrementally to the well’s capacity. Each rate shall be held constant for 30 minutes. Water level readings shall be taken and recorded every five (5) minutes. At the final rate, the test will be continued for the remainder of the 24 hours. The water levels will be recorded every 30 minutes for the next two (2) hours and then hourly for the remainder of the test. Recovery will be measured for 30 minutes before pulling the pump. Before the pump is removed, the Contractor shall notify the City of Dayton, so that the City of Dayton can witness and record the final rate. The payment for the recovery time shall be included in the unit price bid for Item 11, “Recovery Time – 2 Hrs/Well”.

Water Sample

Near the end of the 24-hour pump test, the City of Dayton’s Water Laboratory personnel shall take a water sample. The contractor shall notify the City of Dayton of the starting time of the pump test and the best time to take the water sample. The payment for the water sample shall be included in the unit price bid for Item 10, “Test Pumping 40” X 26” Well at 3,150 GPM”.

Acceptance of Well

Acceptance of newly constructed wells shall be based on well production of a minimum of 2500 gpm. If well production is below acceptance rates, further direction shall be given by the City of Dayton to repair or replace the well.
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Additional Details
No
Rosalind Bertolo
937-333-3755
rosalind.bertolo@daytonohio.gov
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