B08_Attachment_2_Statement_of_Work.pdf

140G0123Q0068 Attachment B Statement of Work

STATEMENT OF WORK

USGS CARIBBEAN-FLORIDA WATER SCIENCE CENTER

DRILLING, CORE COLLECTION AND CONSTRUCTION OF SALTWATER INTRUSION MONITORING

WELL IN PUERTO RICO

1.0 SCOPE AND LOCATION

1.01 The USGS Caribbean-Florida Water Science Center (USGS-CFWSC) is requesting bids for rotosonic drilling, core collection, and construction of a saltwater intrusion monitoring well in support of a research project in the South Coast Aquifer in Puerto Rico.

1.02 Pending municipal approval and permitting, the tentative well site is on municipal property in Salinas, Puerto Rico (Figure 1). If approvals are not granted for this site, an alternative nearby site will be chosen.

1.03 The final depth of the well will be depth to bedrock plus 10 ft or the maximum depth capability of the driller’s equipment, whichever is shallowest. Based on limited existing information, we anticipate that the depth to bedrock should be between 100 and 200ft.

1.04 The work to be performed under this contract shall, in general, include the furnishing of all labor, material, equipment, supplies, and incidentals necessary for drilling, collecting core, and monitoring well installation.

1.05 The work shall include, but not be limited to the following:

A. procuring necessary permits (Section 3), B. protection of existing works and vegetation (Section 6), C. ensuring public safety and site security (Section 7), D. rotosonic drilling and core collection (Section 8), E. maintaining drilling logs (Section 9), F. well installation (Sections 10-13), G. clean-up and site restoration (Sections 14-15).

1.06 The Contractor shall be prepared and willing to commence work as soon as possible after notification of acceptance of proposal and shall complete all work in the shortest amount of time practicable.

1.07 The USGS shall issue purchase order to the Contractor outlining the location and details of the work to be performed.

2.0 SPECIAL CONDITIONS

2.01 The contractor shall have the immediate ability to provide all operational equipment, in good safe operating condition, necessary to conduct rotosonic drilling, core collection, monitoring well installation, and well development. This includes:

A. Ensuring that a freshwater supply with a chloride concentration not exceeding 100 mg/L is available. If an adequate freshwater supply is not available locally near the drilling sites, the Contractor shall truck in water that meets this specification.

B. If there is no available electrical power at the site, the Contractor shall provide his own source of power.

2.02 The contractor shall have the immediate ability to provide a crew with the operational knowledge needed to operate and maintain the equipment necessary to conduct rotosonic drilling, core collection, and well installation.

2.03 The Contractor shall not drill or perform any work which creates noise or requires bright lights that can be seen from other properties other than between the hours of 8:00 A.M. and 6:00 P.M., Monday through Friday. Weekend work is to be avoided. Exceptions due to technical difficulties encountered during drilling must be pre-approved by USGS staff. Efforts will be made to locate wells in municipal/park properties where more flexible hours may be allowed. Local municipal codes and landowner conditions must be observed.

3.0 PERMITS AND LICENSES

3.01 The Contractor shall be licensed by the commonwealth of Puerto Rico and shall comply with all regulations and requirements of the Commonwealth and Municipality.

3.02 The Contractor shall procure all licenses or other permits, if any, and pay all taxes, fees, charges and give notices necessary and incident to the lawful prosecution of the work. Every effort is being made to place the well on municipal property, and USGS- CFWSC personnel will help coordinate with the municipality to obtain municipal approvals. Costs related to permits will be reimbursable to the contractor as provided in the Unit Price Sheet.

4.0 MATERIALS AND WORKMANSHIP

4.01 All materials and workmanship shall be of the best quality and shall be subject to the approval of the USGS-CFWSC. No deviations from the provisions of these detailed Specifications herein shall be made without written approval of the USGS-CFWSC.

4.02 Only first-class work shall be performed, and all materials furnished in carrying out this Contract shall be of character and quality required by these Specifications. Where no standard is specified for such work or materials, they shall be the best of their respective kinds. Any unsatisfactory work done or materials furnished at whatever time they may be discovered shall be immediately removed and satisfactorily replaced by the Contractor when notified to do so by USGS-CFWSC personnel. Upon the completion of the purchase order, the entire work shall be delivered to the USGS-CFWSC in satisfactory working condition.

5.0 STORAGE OF MATERIALS

5.01 Materials shall be stored as to insure the preservation of their quality and fitness for the work. When considered necessary, they shall be placed on wooden platforms or other hard clean surfaces and not on the ground and shall be placed as to facilitate proper inspection. Other private property shall not be used for storage purposes without the written permission of the USGS-CFWSC. If necessary, the USGS will help assist the contractor in communications with the municipality about providing a potential staging area. No guarantees are made of staging area availability. If no staging areas can be secured the contractor will charge a unit price for mobilization and demobilization of equipment.

6.0 PROTECTION OF EXISTING WORKS AND VEGETATION

6.01. The USGS-CFWSC will designate the general location where work will be performed. After the general location has been established, the Contractor shall call for a mark out of all utilities, i.e. electric, gas, water, sanitary sewer, drainage, telephone, irrigation, street lighting, tunnels (rail or auto) or any other underground appurtenances within the area. Upon completion of the mark out of utilities, the Contractor, with the concurrence of the USGS-CFWSC, shall determine the actual drilling site, which allows for safe drilling and does not interfere with any underground utilities or appurtenances.

6.02 All existing structures, piping, utilities, fencing or materials, “herein refer to as properties”, within each site area shall be protected against damage as may be required by the USGS-CFWSC. The Contractor shall be responsible for any damage caused by the contractor’s error, accident, or negligence.

6.03 Although not guaranteed, USGS will attempt to select a drilling location that does not require tree and shrub trimming or grubbing. If required, trimming and grubbing shall be conducted by the contractor and adhere to the following:

A. The USGS-CFWSC will establish the limits of the Work and will designate all trees, plants, shrubs and other items to remain. The Contractor shall protect and preserve all items designated to remain.

B. Trimming shall be in accordance with good tree surgery practice.

C. In areas where Hand Clearing is designated by the USGS-CFWSC, no equipment on wheels or tracks shall be used. Care shall be taken to ensure that the grass, moss cover, or the natural ground is not disturbed. Stumps and very small trees shall be cut flush with the ground, except that in areas within four feet or more of embankment cover, stumps may be cut off 6 inches above the natural ground.

D. The Contractor will be responsible for securing a disposal site for any vegetation and debris that is removed, obtain written permission of the owner of the disposal site, and secure any required permits for the disposal. If requested by the USGS-CFWSC, the Contractor shall furnish the permit numbers of all required permits.

E. The cost of securing a disposal site shall be borne by the Contractor.

7.0 ENSURING PUBLIC SAFETY AND SITE SECURITY

7.01 The Contractor shall be responsible for preventing access to equipment and the borehole, both for the safety of the public and security from theft. This responsibility includes times when drillers are not on site (weekends, nights, and down times) as well as times when drillers are present on site.

7.02 The Contractor shall furnish and install a temporary fence as directed by USGS personnel for safety reasons.

7.03. The Contractor shall protect and maintain the temporary fence at the site until the drilling equipment is removed. The Contractor shall then remove and legally dispose of the temporary fence around the well site.

7.04 The Contractor shall comply with all OSHA and EPA requirements regarding heavy equipment, electrical and mechanical operations, storage of compressed and flammable gases, and storage and handling of hazardous materials.

7.05 The Contractor shall conduct all operations in a clean and sanitary manner. No nuisance shall be committed in the work area. The Contractor shall either use proper waste receptacles or leave the site whenever the necessity arises. If necessary, portable toilet facilities shall be provided and paid for by the contractor for the use of his personnel at the site. Any portable toilet facilities provided by the Contractor shall be maintained in a clean sanitary condition.

7.06 The Contractor shall keep the site free of debris and shall remove all waste from the site weekly. The entrance way to the drilling sites shall be kept free of rubbish, dirt and other material.

8.0 DRILLING AND CORE COLLECTION

8.01 The Contractor shall provide all labor, tools, personnel, and materials required to perform and complete the drilling in a safe and efficient manner. If the Contractor's equipment is judged unsatisfactory, the Contractor will be expected to replace the unsatisfactory equipment with equipment which is acceptable to the USGS-CFWSC, and within sufficient time to complete the Contract on schedule.

8.02 The Contractor shall use the rotosonic method to drill boreholes for the purpose of collecting core and installing a 2-inch monitoring well in the borehole.

8.03 The borehole is to be drilled to bedrock and an additional 10ft, or to the maximum depth of the drilling equipment, whichever is shallowest. Based on limited existing information, we anticipate that the depth to bedrock should be between 100 and 200ft.

Because the depth to bedrock is uncertain, the final well depth cannot be determined exactly prior to drilling.

8.04 If site conditions require the use of fluids, only fresh water (chloride concentration < 100 mg/L) or Bentonite Drilling Fluid, as distributed by Johnson Screens, Inc., or equivalent, shall be used. No drilling fluid additives that could create an environmental hazard, no iron fillings, and no iron-based additives are to be used. The driller will monitor and maintain the drilling fluid integrity when encountering saltwater intruded aquifers.

8.05 It is expected that the well will be drilled into unconsolidated deposits of gravel, sand, silt and clay and weathered bedrock. Geological conditions at the well site are not guaranteed by the USGS-CFWSC.

8.06 Any geologic materials such as hardpan and boulders encountered during drilling, shall be demolished, and disposed of by the Contractor. USGS intends to select a drilling location where drilling speed and efficiency can be maximized. However, there is no guarantee that boulders will not be encountered in the subsurface and in some extreme cases moving the drill rig and restarting the borehole may be required. The nature of drilling requires dealing with variable subsurface geology which could include boulders, hardpan, and other materials.

8.07 The Contractor shall take every precaution and measure to ensure that the borehole is drilled true and plumb. Plumbness of the well shall be checked frequently during the drilling process. Significantly deviated boreholes are unacceptable. A 64 inch long, 1.4-inch diameter geophysical probe must be able to pass unimpeded through the entire depth of the completed well.

8.08 The contractor will collect continuous core during drilling. These cores will be delivered in plastic sleeves to USGS personnel in the field for preliminary geologic logging, boxing, and labelling. The contractor will indicate the core tops and bottoms when they layout the core for USGS personnel. The contractor will provide safe access for USGS personnel to inspect the core and shall accommodate USGS personnel in retrieving the cores, including moderating drilling rates, if necessary.

9.0 DRILLING LOGS

9.01 The Contractor shall furnish the USGS with a daily drilling record. This record shall describe the following: geologic materials and depths encountered, drilling rate, time, depth, diameters and lengths of drill rod and casing, any unusual occurrences, or problems during drilling. USGS on-site personnel will also keep a log and some of this information may be kept in the USGS log by mutual agreement.

10.0 WELL CASING AND SCREEN INSTALLATION

10.01 Well casing and screen installation shall be in accordance with ASTM D5092. The Contractor shall consult with and obtain concurrence with the USGS-CFWSC representative to confirm the final well construction details.

10.02 The Contractor shall provide all casing together with required O-rings and pipe sealant/cement, couplings, plugs, caps, fittings, or other parts necessary to satisfactorily complete the casing installation.

10.03 No metal shall be used anywhere in well construction. This includes metal screws, clamps, screens, or spacers. Well centralizers can be used to keep the casing straight and plumb, however no metal can be used for, or to attach these centralizers. Even small metal screws can greatly interfere with the electromagnetic logs the USGS plans to collect and cannot be used.

10.04 All screen and casing sections shall be cleaned and bagged prior to delivery.

10.05 Casing shall be 2-inch-diameter, flush threaded, polyvinyl chloride (PVC) with o-ring seals. The contractor shall be responsible for ensuring that the strength properties of the casing are adequate for conditions in borehole.

10.06 If the bedrock surface is reached, the Contractor will install a 5-foot long, 2-inch diameter, open-ended 0.010-inch slot size well screen just above the bedrock surface. If the bedrock surface is not reached, the Contractor will install a 5-foot long, 2-inch diameter, 0.010 -inch slot size well screen 10 ft above the final borehole depth.

10.07 The Contractor will install 10 feet of 2-inch PVC casing below the screen (a sump) to allow geophysical logging equipment to pass through the full length of the screen. An end cap will be placed on the bottom end of this sump.

10.08 The final casing must be watertight and free of leaks, or the well must be replaced free of additional charge.

10.09 Casing and screen shall be installed sufficiently plumb to allow installation or tremie pipes for proper grouting of the casing and operation of all USGS sampling and monitoring equipment. A 64 inch long, 1.4-inch diameter geophysical probe must be able to pass unimpeded through the entire depth of the completed well.

11.0 ANNULAR SPACE BACKFILL MATERIAL

11.01 All materials installed to fill the annular space shall be installed using a tremie pipe rather than just poured into the annular space from the surface with the hope that they will sink to the bottom and not bridge at some shallower depth.

11.02 Frequent measurements must be made to ensure that all materials are installed at the proper depths. The depths of all layers of materials shall be measured and these depths shall be recorded in a log to verify that they have been properly emplaced.

11.03 Annular space below the well screen - The annular space below the well screen shall be grouted with bentonite grout, a grout consisting of cement and bentonite, bentonite pellets, or a combination of these materials. This grout layer shall extend from about 3 feet below the screen to the full well depth. Extreme care and frequent measurements are needed to ensure that this grout does not reach the screen.

11.04 Filter pack - The Contractor shall furnish and place clean silica sand filter pack in the annular space between the hole and the well screen, in the depth interval extending from approximately 3 ft below to 3 ft above screen. The particle size of the filter pack shall be designed to keep fines in the aquifer from plugging the well.

11.05 Fine sand layer above the filter pack – 2 to 4 foot layer of fine sand shall be installed above the filter pack to prevent any grout or bentonite from leaking down into the filter pack.

11.06 Bentonite pellet layer – At a minimum, a 2- to 4-ft bentonite pellet seal overlying the filter pack is required to ensure proper well completion. This layer must be bentonite pellets rather than chips. Bentonite chips may hydrate too rapidly and cause clogging of the tremie pipe or bridging.

11.07 The materials of the annular seal in the saturated zone shall be designed to consider differences in the permeability of the strata of the aquifer. Where highly porous strata occur, the annular space shall be filled with sand or pea gravel, and where relatively impermeable strata occur, the annular space shall be sealed with bentonite grout. This will allow any saltwater flowing through the aquifer to get near enough to the well so that it can be detected by the induction logs.

11.08. Annular seal in the unsaturated zone - The unsaturated part of the aquifer will be filled with neat cement grout to prevent drying out and cracking of the annular seal.

Cement grout will be installed in lifts of no greater than 20 feet in a day to prevent overheating during curing which might warp or cause bends in the casing.

12.0 SURFACE COMPLETION

12.01 A vent hole shall be drilled in the casing near the surface, and a locking, watertight well plug (i.e. a locking nylon expansion plug or a water tight hinged locking cap) must be installed.

12.02 Surface completion will include a 3-ft x 3-ft x 12-in cement pad that slopes slightly away from the well.

12.03 The Contractor shall coordinate with USGS personnel to ensure that the surface casing is compatible with monitoring equipment that the USGS plans to install in the well. Final site selection will dictate whether the well will be completed below grade or extend above the ground surface. For a below grade completion, the well must be enclosed in a metal water-tight monitoring well manhole with a bolt down lid and gasket to prevent tampering. The well recess will have coarse sand or pea gravel in the borehole at least three feet below the cement pad to allow drainage of rainwater. For above ground surface completion, the contractor will install a protective steel outer surface casing with a weep hole just above the concrete pad and a hinged locking metal cap.

12.04 Whether the final well completion is below grade or above ground, the protective casing, well pad, and upper most part of the annular seal shall be designed to make sure the protective casing will drain and not hold water.

13.0 WELL DEVELOPMENT

13.01 Upon well installation, the contractor shall have the immediate availability of equipment necessary to develop the well using standard methods including: (a) using a surge block combined with bailing or pumping, (b) bailing, or (c) pumping and backwashing.

13.02 The Contractor will develop the well using standard methods until the water is clear and free of suspended sediment and drilling fluids and is pumping at an acceptable discharge rate.

13.03 The Contractor will take care to ensure that the well is not damaged by the well development process.

14.0 SITE RESTORATION

14.01 Site restoration must be completed within 30 days of well completion.

14.02 Once drilling and well installation are complete, the Contractor is required to restore the site to original grade and original or better condition. To assure complete site restoration, we recommend the Contractor take photographs prior to placing equipment on the site. USGS personnel must approve site restoration.

14.03 If topsoil needs to replaced as part of the site restoration, the Contractor shall use suitable topsoil stockpiled by the Contractor from his work. Additional topsoil may be required from off site as determined by the USGS-CFWSC.

14.04 Any topsoil that is placed during site restoration is to be kept free from roots and stones.

14.05 Topsoil that is placed as part of site restoration shall be spread to sufficient depth above grade to allow for settlement, raked to remove stones and debris and lightly compacted.

14.06 Seeding to restore damaged grassy areas is to be done when directed by the USGS CFWSC representative.

14.07 No seeding shall be done until topsoil has been appropriately placed.

14.08 The Contractor is responsible for ensuring that bags of seed comply with any agricultural seed laws in the local area or Puerto Rico.

15.0 SITE CLEANUP

15.01 After completion of the work, all tools, appliances, surplus materials, temporary drainage, rubbish and debris incidental to the work shall be removed from site within one week of well completion.

15.02 Backfill excavation and vehicular ruts shall be dressed to conform to the existing landscape or terrain within 30 days of well completion

15.04 Utilities, structures, roads, fences, or any other pre-existing items which must be repaired or replaced due to the Contractor’s negligence are the Contractor’s responsibility and the Contractor must accomplish repair or replacement within 30 days of well completion.

15.05 The Contractor will be responsible for the disposal of drill cuttings, rock core, grout or bentonite slurry, and other solid or liquid materials bailed, pumped or otherwise removed from the borehole during drilling, well installation and completion procedures. The Contractor shall dispose of these materials within all appropriate regulatory requirements. If material is hauled from the site, the Contractor will provide the USGS with documentation (receipts and/or photographs) to verify the volume of material hauled.

Figure 1. - Tentative drilling location in the city of Salinas.