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2004-08-30 Special Provisions I I I I I I I I I I I I I I I I I I I Page I. 2. 3. 4 . 5. 6. PAGE 7. 8 . 9. 10. II. 12. PAGE 13. 14. 15. 16. 17. 18. 19. 20. PAGE 2l. 22. 23. II. I. 2. PAGE 3. 4. 5. III. I. 2. 3 . SPECIAL PROVISIONS TABLE OF CONTENTS 1 Project Foreman and Preconstruct ion Meeting Construction Staking and Observation Construction Limits Existing Utilities Contractor-Engineer-Inspector Relationship 2 Subcontractors Incidental Items Responsibility Starting Time Permit Requirements Compaction 3 Testing Protection of Existing Utilities Specifications Which Apply Shop Drawings Standard Plates Subsurface Exploration Clean-Up Grading 4 Existing Draintile Payment and Performance Bond Certificate of Insurance Utilities - General Bedding Materials 5 Connections Ductile Iron Sanitary Pipe Compaction Under Services Watermains Operations of Existing Gate Valves Water for Construction Water Service Group ~ I I I I I I I I I I I I I I I I I I I 4. PAGE 5. 6. 7. 8 . 9. 10. 11. PAGE 12. IV. I. 2. 3 . 4. 5. PAGE V. I. 2 . 3. 4. 5. 6. 7. PAGE 8. VI. I. 2. 3. 4. Classification of Pipe 6 Tracer Wire Plastic Film Wrap Thrust Restraint Water Service Watermain Testing Watermain Testing Completion Form Method of Measurement - Watermain 7 Basis of Payment - Watermain Utilities - Sewer Sanitary Sewer Testing Manhole Castings Sewer Service Group Manhole and Catch Basin Protection Catch Basin and Manhole Openings 8 Street and Grading Street Construction Test Rolling Draintile Geotextile Fabric Select Granular Borrow Seed, Mulch, Disk Anchor Excess Material 9 Existing Curb & Gutter Erosion Control Protection of Downstream Amenities Erosion Control Bale Checks Silt Fence Wood Fiber Blanket '!i\ I I I I I I I I I I I I I I I I I I I SPECIAL PROVISIONS PROJECT NO. 04137 I. GENERAL 1. PROJECT The project consists of the construction and installation of watermain, sanitary sewer, storm sewer, and street in Albertville, Minnesota. An anticipated start date for the Project is August 30, 2004. The water, sanitary sewer and storm sewer shall be completed by September 17, 2004. The curbing, aggregate base and base course shall be completed by October 4, 2004. The bituminous wear course shall be paved in the summer of the following year and shall be completed after June 15, but before September 1, unless approved by the Engineer. The bituminous wear course paving may be delayed up to two construction seasons after paving of the bituminous base coarse, if determined necessary by the Engineer. The Contractor shall be subject to the provisions of Article 14 of the Supplemental Conditions for failure to meet these completion dates, as a whole or in part. 2. FOREMAN AND PRECONSTRUCTION MEETING Before work is initiated, a preconstruction meeting shall be held between the Engineer, Contractor, Utility Companies and other involved parties, if any. The Contractor will present to the Enoineer an estimated schedule for completion of various portions of the proiect. The Contractor shall inform the Engineer who the foreman on the project will be. The foreman shall be on the job at all times. The foreman shall be responsible for all phases of the project, including work done by the General Contractor and the subcontractor. Engineering decisions with regard to the work done by subcontractors shall go through the General Contractor and specifically the foreman for the job. 3. CONSTRUCTION STAKING AND OBSERVATION The Contractor shall give the Engineer at least two (2) working days notice for any grade and line stakes or inspection that he requires for proper execution of any phase of the project. The Contractor shall preserve these stakes until the work is completed. Restaking required due to Contractor negligence will be the responsibility of the Contractor. The City Engineer's office will provide construction observation on the Project for all future City owned and maintained facilities. The Contractor shall coordinate with the Project Engineer and the City Engineer's office regarding construction activity and progress. 4. CONSTRUCTION LIMITS The Contractor shall confine his activities to the right-of-way or designated construction area. Equipment and material storage or deposition of excavated materials on private property must be approved in writing by the property owners, a COpy of which shall be presented to the Enqineer prior to such storaoe or deposition. Failure to do so will result in immediate suspension of work until such approval has been obtained or materials removed, and area restored to its previous condition or better. 5. EXISTING UTILITIES The Contractor shall be in communication with the respective utility companies to coordinate their schedule with any location work that is required. 'OlI 6. CONTRACTOR-ENGINEER-INSPECTOR RELATIONSHIP The Engineer will not be responsible for the construction means, controls, techniques, sequences, procedures, or construction safety. All phases of the project shall proceed in accordance with OSHA safety requirements. The presence of the Engineer or his agents or employees on the job site shall not relinquish the Contractor of this responsibility or hold the Contractor harmless for the quality of workmanship or defects in materials. 1 I I I I I I I I I I I I I I I I I I I 7. SUBCONTRACTORS All subcontractors that the General will use shall be shown on the proposal form. Any other subcontractor will not be allowed without explicit written permission by the Engineer. The General Contractor shall coordinate all work between his subs and the Engineer. The Engineer will not correspond directly with any subcontractor. Anyon-site meetings that are held will be conducted only if the General Contractor's foreman is present. 8. INCIDENTAL ITEMS Any and all additional items of work or other items that must be done to fully complete this project shall be incidental to the bid items as bid. 9. RESPONSIBILITY The General Contractor shall be fully responsible for all work that is performed on this project. It is the General Contractor's responsibility to see that all specifications and testing requirements are followed. 10. STARTING TIME The Contractor shall not engage in or permit construction activities involving the use of any kind of electric, diesel, or gas powered machine or other power equipment, except between the hours of 7:00 A.M. and 6:00 P.M. on any weekday with no work on Sundays or legal holidays. 11. PERMIT REQUIREMENTS Permit applications have been submitted to the Minnesota Pollution Control Agency and the Minnesota Department of Health in order to minimize any potential delays in the project. The Contractor should therefore contact these agencies to determine if there are any special conditions they may have which should be included in the bid. The contractor will be required to comply with all the requirements that these agencies may have. No change orders will be considered for complying with these requirements; 12. COMPACTION The required compaction of all lot grading shall be 95% of the standard proctor density. The required compaction within roadways and driveways shall be 100% of the Standard Proctor Density from finished grade to a point three (3) feet below finished grade and 95% of the Standard Proctor Density from three (3) feet or greater below finished grade. The backfill around and to 12" above the pipe (sanitary sewer, storm sewer and watermain) shall be compacted by mechanical hand tampers. The required compaction shall be 95% of Standard Proctor Density. All trenches within roadways shall be compacted to 100% of Standard Proctor Density in the upper three (3) feet of the trench. At the time of the compaction, the moisture content of the backfill soils shall be not less than 75% or more than 115% of optimum moisture content. The Contractor shall add water or dry the soils until this requirement is met. If moisture content greater than 125% of optimum moisture content is encountered, the Engineer shall revise the compaction requirements to meet the best interests of the Owner. Moisture adjustment of the soils shall be incidental to the pipe installation unit price. All trench areas not conforming with these requirements shall be excavated and recompacted. The Contractor shall supply the Engineer at the time of the preconstruction meeting a list of equipment that will be used for backfilling and compaction operation. The Engineer reserves the right to shut down work on the project if this equipment is not utilized during such backfilling and compaction operations. A maximum 12" lift shall be used. Smaller lifts may be required to obtain the specified d~nsity."lf 12" lifts are not utilized, the trench will be completely re-excavated and recompacted in order to achieve maximum compaction lifts of 12". The bedding material around all pipes shall be compacted in maximum 6" lifts. 2 I I I I I I I I I I I I I I I I I I I 13. TESTING An independent testing lab shall test the backfill for the required density as the backfilling compaction progresses. If the tests fail, it shall be the Contractor's responsibility to pay for retesting those areas following compaction. All trenches for watermain, sanitary sewer, storm sewer and services shall be tested for the required compaction density in conformance with the compaction requirements. The trench shall be tested at approximately 100-foot intervals at two to three depth locations, depending on depth. One test shall be taken next to the pipe, the second shall be taken at two feet below subgrade and at the midpoint of the trench. Compaction around every manhole and gate valve shall be the same as for the trenches. Tests shall be taken at every manhole and gate valve at the three depth locations as stated above. The Engineer may change test locations and depths at his discretion. The Engineer may add or delete tests at his discretion with no change in the unit price. The contractor shall be responsible for coordinating his schedule with the testing firm and all test results shall be documented with respect to plan stationing, depth and location. Copies of all test reports shall be given to the engineer no more than one week after the test was taken. Engineer shall, within 24 hours, be notified in person, by phone or by fax of any failing tests. 14. PROTECTION OF EXISTING UTILITIES The Contractor shall use utmost care during his operations and particularly during manhole adjustments to keep gravel and debris from entering sewer manholes. In the event of debris or gravel entering the sanitary sewer lines, these lines shall be jetted by Roto-Rooter or other approved company at the expense of the Contractor. Flushing of debris or gravel down the sanitary sewer or storm sewer lines will not be allowed. 15. SPECIFICATIONS WHICH APPLY The Minnesota Department of Transportation "Standard Specifications for Construction", 2000 Edition, together with all supplements thereto, shall govern except as superseded by the attached general Conditions or modified herein by the Special Provisions and attached specifications. Conversion of metric measurements is to be done in accordance with ASTM E380.27 16. SHOP DRAWINGS The Contractor shall submit shop drawings for approval by the Engineer for manholes to be used on the project. A minimum of three copies of each shall be supplied to the Engineer. 17. STANDARD PLATES All references to standard plates MHD shall mean the "Standard Plates" of the Minnesota Department of Transportation. All other reference to standard plates shall mean those details attached to the plans. 18. SUBSURFACE EXPLORATION Soil borings were taken and are on file at the office of the Engineer. The Contractor may review the soil engineer's report at the office of the Engineer during normal business hours. The use of this data by the Contractor shall not relieve the Contractor of his duty to examine the site per Section 6 of the Instructions to Bidders. 19. CLEAN-UP When the work has been completed, the Contractor shall remove from the site all extra material, equipment, debris and other supplies. The site shall be cleaned up as is necessary to1eave all property in substantially the same condition as it was before the project. 20. GRADING All grading for lots, pads, ponds and street subgrade shall be completed in area (by others) before utility or street construction is commenced in that area. Site grading will be required of the Contractor after construction to restore the site to its initial condition. All grading work by the Contractor for restoration purposes shall be incidental to the unit prices bid. 3 I I I I I I I I I I I I I I I I I I I 21. EXISTING DRAINTILE Existing tile lines encountered are to be immediately reported to the Project Engineer. All necessary reconnection or replacement of encountered tile lines shall be incidental to utility installation. 22. PAYMENT AND PERFORMANCE BOND Payment and performance bonds shall name the Owner and the City of Albertville as obligee of the bonds. 23. CERTIFICATE OF INSURANCE The Certificate of Insurance must read as follows: Certificate Holder: Woodside Communities of Minnesota, Inc. 13736 N.E. Johnson Street Ham Lake, MN 55304 Additional Insured: City of Albertville Meyer-Rohlin, Inc. SEH Cancellation Clause: Should any of the above described policies be materially changed, suspended, or cancelled before the expiration date thereof, or fail to be renewed upon their expiration, the issuing company will mail 30 days written notice to the named certificate holder. II. UTILITIES - GENERAL 1. BEDDING a. All water main, sanitary sewer mains and services shall be bedded according to the standard plate for PVC pipe bedding. The bedding material shall conform to the requirements of Section 2600.2A1 of the Standard Utilities Specification. b. For watermain bedding, refer to Joint Powers Water Board Construction Requirements and addendum attached thereto. A mechanical hand tamping machine must be used around all water and sanitary sewer pipe to compact the bedding and initial fill. c. All concrete storm sewer pipe bedding shall be ordinary bedding consisting of natural, on- site soils, except in cases where the Engineer directs otherwise. The fill material around the pipe shall be less than one inch in diameter and also free of any organic material or foreign objects. All HDPE pipe bedding and embedment shall be according to standard detail 3.024. Embedment material shall be MnDOT Specification 3149.2D modified to 100% passing the 1 inch sieve. 2. MATERIALS ~ a. Refer to Joint Powers Water Board Construction Requirements and addendum attached thereto. b. All sewer mains and service wyes shall be constructed utilizing PVC, SDR 35 sewer pipe with gasketed joints. Sanitary sewer mains placed 20 feet deep or greater shall be PVC, 4 I I I I I I I I I I I I I I I I I I I SDR 26 sewer pipe with gasketed joints. All sewer services and fittings shall be constructed utilizing PVC, SDR 26 sewer pipe with gasketed joints. c. All RCP storm sewer pipe shall be Class III with rubber gasketed joints. The last three joints on any flared end line must be tied. All HDPE storm sewer pipe shall conform to the requirements of MnDOT 2503, as identified in MnDOT Technical Memorandum 91 079b01, dated April 2, 1991. Soil tight gasketed joints are to be provided unless noted otherwise on the Plan. Deflection testing shall be done at the option of the Engineer and is considered incidental to the Project bid. The flared end sections for the polyethylene pipe shall be constructed of galvanized steel materials. 3. CONNECTIONS All connections to existing lines are incidental unless specified as separate item on proposal form. Payment will be made based upon the fittings and pipe length used. 4. DUCTILE IRON SANITARY PIPE All ductile iron to PVC pipe connections shall be incidental to the unit bid price for sanitary sewer installation. 5. COMPACTION UNDER SERVICES Any soil that is subcut from below a service must be compacted back in place at 100% standard proctor density prior to laying the service. Density tests must be taken to confirm the density. If the soil is not compacted to 100% standard proctor density, then crushed rock must be compacted and placed below the service in order to ensure no movement. Use of crushed rock shall be at the Contractor's expense. III. WATERMAINS 1. OPERATION OF EXISTING GATE VALVES The Contractor shall not turn any existing gate valves to charge new watermain lines. Only the Joint Powers Water Board operator can turn an existing valve. The Board has adopted a policy such that watermain under construction will not be allowed to be charged from existing watermain. The Contractor will be responsible for charging watermain lines under construction from a water truck or other means and shall be incidental. Procedures for obtaining water are noted in the item titled "Water for Construction". Water from existing lines will only be allowed to be used for flushing of new watermain when obtaining bacteria test samples. 2. WATER FOR CONSTRUCTION Water for construction purposes may not be taken from any hydrant within the city of Albertville. Water may be purchased and obtained from the Joint Powers Water Board at the hydrant in front of the Board's pumphouse, located at 11100 50th Street Northeast in the city of Albertville. A permit per day must be obtained from the clerk of the Joint Powers Water Board after paying the required fee. Water may be obtained from this hydrant only after prior arrangements have been made with the clerk of the Joint Powers Water Board for each day it is to be used. Contact Joint Powers Water Board at 763-497-3611. 3. WATER SERVICE GROUP A water service group shall include the curb stop, the service corporation, and any ott,ler parts (excluding the copper pipe necessary for the installation of the water service). All materials shall confolrrTl to AWWA Standards. Tapping saddle shall be used for service corporations on all PVC pipe. Water services shall be extended beyond the curb box to a point under the building pad. 4. CLASSIFICATION OF PIPE Water distribution pipe shall be C900 PVC. 5 I I I I I I I I I I I I I I I I I I I 5. TRACER WIRE Tracer wire shall be installed along the pipe. The wire shall be a solid 12 gauge copper with plastic coat. Copper wire nut splices will be allowed as well as 3M cast kits. Main line tracer wire must stay intact and cannot be looped up valve boxes, hydrants, or services. Separate splice wires must be used. 6. PLASTIC FILM WRAP Water distribution fittings shall be wrapped in plastic film. The wrap shall be "tube" type having 8-mil thickness. A 2 inch wide polyethylene adhesive tape shall be used to secure the tube of film to the pipe. If core-blue bolts are used with epoxy fittings, then only hydrants, valve, boxes, and bitumastic coated tie rods need to be poly wrapped. 7. THRUST RESTRAINT All water main, valves, services, fittings, stubs, extensions, blind flanges, and plugs used for retaining water pressure must be tied with "megalug" joint restraints or accepted equal. All bare metals shall have two coats of bitumastic or accepted equal (aerosol spray is not acceptable). 8. WATER SERVICE Prior to the shutoff of any water, the Contractor shall notify the Joint Powers Water Board and the affected property owners of his working schedule. The Contractor shall give notice 48 hours in advance of the start of the work. The work done during this time shall be done in an efficient manner so that as little inconvenience as possible is caused. The Joint Powers Water Board will not shut off water prior to 9:00 a.m. 9. WATERMAIN TESTING Refer to Joint Powers Water Board Construction Requirements. 10. WATERMAIN TESTING COMPLETION FORM The Contractor shall submit to the Engineer completed Watermain Test Report Form, as attached to the Joint Powers Watermain Construction Requirements, for all pressure, conductivity, and bacteria test performed on the Project. The contractor shall note the dates the tests were performed, names of witnesses to the tests and sign the form. 11. METHOD OF MEASUREMENT - WATERMAIN The following revisions are to be made to the Standard Utilities Specifications, Section 2611.4: A. Delete Section 4E in its entirety and insert the following in its place: "E. Hydrants Hydrants shall be measured on a per-unit basis. The unit includes the hydrant, concrete base, crushed rock, tar paper or plastic cover, hydrant flag, and blocking or restraining devices." B. Delete Section 41 in its entirety and insert the following in its place: "I. Fittings Fittings of each type shall be measured on a per-unit basis and include all required accessories." C. Delete Section 4K in its entirety and insert the following in its place: ilK. Granular Materials " '. Granular materials used for bedding, encasement, etc. for the watermain shall not be measured for separate payment." 6 I I I I I I I I I I I I I I I I I I I 12. BASIS OF PAYMENT - WATERMAIN The following is in addition to the Standard Utilities Specifications, Section 2611.5: Hydrants shall be paid for at the unit contract price per each, including installing the hydrant, concrete base, crushed rock, tar paper or plastic cover, hydrant flag, and blocking or restraining devices. Fittings shall be paid for at the contract unit price per each type and size, including all accessories, installation and blocking. Granular materials used for bedding, encasement, etc. for the watermain, shall be incidental to the watermain installation. IV. UTILITIES - SEWER 1. SANITARY SEWER TESTING The Contractor shall utilize PVC for construction of the sanitary sewer lines. The Contractor shall pay particular attention to the bedding requirements for PVC pipe. The PVC pipe shall be tested for a maximum pipe wall deflection of 5% of the normal pipe size. This testing shall be done in the presence of the Engineer at the completion of all backfilling operations. If any portion of the line is not within the maximum pipe wall deflection of 5%, this portion shall be re-excavated, properly bedded and tamped, and the trench recompacted and tested for density at no additional expense to the Owner. The line shall then be tested again for pipe wall deflection. Deflection testing shall not be done prior to the pipe being in place for 30 days. 2. MANHOLE CASTINGS All sanitary sewer manhole castings shall be Neenah R-1642, or approved equal, with the type B sel- sealing lid with concealed pickholes and the appropriate name stamped on it. 3 SEWER SERVICE GROUP A sewer service connection shall include the wye and bends, as required to serve each connection, regardless of service type. Sanitary sewer service ends shall be marked with steel fence posts. Payment shall be by the individual service connection made and shall include all materials, labor and equipment necessary for its installation. The sewer service connection does not include the service pipe, which shall be paid under a separate bid item. 4. MANHOLE AND CATCH BASIN PROTECTION Once the manhole and catch basin barrel sections have been set, the opening shall be covered with a protection plate (1/2" steel or 1" wood). These plates will remain in place during subgrade preparation and Class 5 placement. They shall not be removed until the adjustment rings are ready to be placed permanently with mortar. If drainage access is necessary, a silt fence barrier must be constructed and in place as per detail prior to permanently removing the plate. 5. CATCH BASIN AND MANHOLE OPENINGS Any opening required for placement of pipe into a structure which does not have a pre-manufactured opening or knockout must be bored. Use of hammers or items to crack the structure due to impact will not be permitted. Core drilling of connections to existingmanhoJes shall be incidegtal to the Contract Price. 7 I I I I I I I I I I I I I I I I I I I V. STREETS AND GRADING 1. STREET CONSTRUCTION This project consists of the street construction in two (2) construction seasons. After paving the bituminous base course, all gate valves and manholes shall be adjusted to 3/4" below the top of the base course. No diamonds shall be provided around the gate valves and manholes. Prior to paving the bituminous wear course, all gate valves and manholes shall be adjusted to 3/4" below the top of the finished wear course. Bituminous patching around the gate valves and manholes shall be completed a minimum of 24 hours in advance of the bituminous wear course construction. All bituminous patching shall be performed with a smooth drum roller. Bid items have been provided for adjustment of the manholes and gate valves prior to paving the wear course. These bid items shall include all labor, equipment and materials necessary for removing the bituminous base course from around the structures, raising the manhole or gate valve, re-compacting the disturbed gravel and soil, patching the bituminous base course, and disposal of all excess debris. All manhole adjustments shall be achieved by the use of precast concrete rings 2" or more in thickness. A motar bed shall be placed between all rings between the manhole casting and ring and manhole barrel top and ring. Payment for adjustment of manholes and gate valves shall be made at a rate of 50% of the bid price when the adjustment is made for the base course and 50% when final adjustment is made. 2. TEST ROLLING The Contractor shall be required to test roll the subgrade and the aggregate base in accordance to Article 2.04 of the Street Construction Specifications. The subgrade shall pass the test rolling prior to placement of the aggregate base and the aggregate base shall pass the test rolling prior to placement of the curbing and pavement, respectively. 3. DRAINTILE The Perforated Corrugated Polyethylene (CPE) shall conform to MnDOT Specification 3278 and shall be fabricated with one perforation on the top of the pipe. The geotextile for wrapping the CPE shall be Type I, conforming to MnDOT Specification 3733. The draintile shall be bedded in fine filter aggregate material conforming to MnDOT Specification 3149.2J. The Contractor shall provide one (1) gradation by an independent testing firm on the fine filter aggregate material prior to installation. Draintile behind the curb shall be connected to existing and proposed catch basins. This connection and all equipment, labor, and materials necessary to install the perforated draintile as shown on the plan shall be incidental to the unit bid price for drain tile installation. 4. GEOTEXTILE FABRIC A bid items for geotextile fabric has been included for this Project. This bid item shall only be used if the Enoineer determines that the soil conditions warrant its use. Geotextile fabric shall meet the requirements of MnDOT Specification 3733 for Type V Geotextile Fabric. 5. SELECT GRANULAR BORROW A bid item for select granular borrow has been included for this Project. This bid item shall only be used if the Enoineer determines that the soil conditions warrant its use. 6. SEED, MULCH, DISK ANCHOR Seeding, mulching and disk anchor erosion control quantity may be adjusted in utility construction areas. The area to be seeded will be designated by the Engineer at the time of installation. ...;r. 7. EXCESS MATERIAL Excess suitable material for fill and top soil shall be stored on site at a location designated by the Engineer. The Contractor will deliver and stockpile the material to the location at no additional cost to the Owner. The stockpile shall have slopes no great than 2:1 upon completion. All unsuitable material and construction debris, etc. shall be disposed of off site. 8 I I I I I I I I I I I I I I I I I I I 8. EXISTING CURB & GUTTER There are several existing private road entrances that will need to be removed and replaced with B618 concrete curb & gutter. There also may be the need to remove and replace portions of the remaining private road entrances in order to achieve proper road width and grade. All removal and disposal of concrete curb and gutter, cross gutter, or driveway aprons that is necessary to complete the project shall be incidental to the contract price. Installation of B618 concrete curb & gutter will be paid for at the unit bid price. VI. EROSION CONTROL 1. PROTECTION OF DOWNSTREAM AMENITIES Contractor shall inspect all erosion control facilities on a weekly basis and after rainfalls of 1" or more. Repairs, as needed, shall be made within 24 hours. Repairs shall include but not be limited to: Reconstruction of silt fences and bale checks, replacement of blankets, reseeding, removal of silt and/or water from temporary ponds and permanents ponds and repair of pond slopes and overflows. Need for repair shall be based on facility's ability to function as it was intended. Slopes steeper than 5:1 shall be furrowed periodically, perpendicular to the slope, to deter the creation of wash outs along the slope. The Contractor shall be responsible for all erosion and repair until final acceptance of the Project by the Owner. Contractor shall be responsible for removal of silt and sediment, due to runoff from all areas of the Project. Contractor shall maintain a sufficient supply of erosion control materials (silt fence, wood fiber blanket, hay bales, seeding and rock) on site to expedite repair of damaged erosion control items and protection of newly constructed steep slopes and other erosion sensitive areas. Contractor shall protect all previously constructed erosion control items and immediately repair said items. No previously placed erosion control items shall be allowed without alternate facilities having been constructed. 2. EROSION CONTROL BALE CHECKS Bale checks shall be installed for erosion control purposes as needed and where designated by the Engineer. Bio-roll may be used in lieu of hay bales and is the preferred alternative. 3. SILT FENCE The Contractor shall install erosion control silt fence as shown on the plans prior to any construction with the area unless noted on the plans. Silt fence installation shall conform to the Best Management Practices for Minnesota, Section 6.3. Erosion control fence shall be maintained by the Contractor throughout all construction phases. Silt fence shall be inspected immediately after a rainfall event that creates runoff and daily during prolonged rainfall. Any damage to the fencing shall be repaired immediately. 4. WOOD FIBER BLANKET Installation of wood fiber blanket shall include all grade preparation and seeding of the area prior to installation of the blanket. " 9