11 of 40 Construction of Giresun Wastewater Treatment Plant  Tender Dossier Volume 3 Employer’s Requirements  Section 04: General Requirements for the Execution and Completion of the Works   Quarries and borrow pits,  the Contractor shall describe from where he will extract the  materials and which measures he will take in order to minimize the environmental  impact, during and after the construction period.  The Contractor shall meet the requirements of the relevant environmental authorities and obtain the  required approvals in this respect.  In addition to the above-described measures, protection of the environment related to air,  wastewater, waste, noise, vibration, emission and dust shall be controlled as described below.  4.7.2 Noise Control during Construction  Generally, the Contractor shall ensure that the impact of noise due to construction activities is  minimized through the use of good site management, plant maintenance and communications with  the Municipality and adjoining property owners. Therefore, the Contractor shall employ the best  practical means to minimize noise produced by his operations, including plant maintenance.  All vehicles and mechanical plant used on the works shall be fitted with effective exhaust silencers  and shall be maintained in good and efficient working order for the duration of the works.  Machines in intermittent use shall be shut down in the periods between the works or throttled down  to a minimum. The Contractor shall remove from the works any item of plant, which, in the  opinion of the Engineer, is ineffectively silenced. All compressors shall be "sound reduced" models  fitted with properly lined and sealed acoustic covers which shall be kept closed whenever the  machines are in use. All ancillary pneumatic percussive tools shall be fitted with mufflers or  silencers of the type recommended by the manufacturers. Pumps and mechanical static plant shall  be enclosed by acoustic sheds or screens where directed by the Engineer.  Any plant, such as generators and pumps, which is required to work outside the normal working  hours shall be surrounded by an acoustic enclosure to the approval of the Engineer which shall  restrict the noise level to not less than 5 dB(A) below levels quoted hereunder. Piling, including  temporary piling, shall be carried out by recognized noise reduced systems. Piling should not be  carried out before 07:00 or after 20:00 hours without the written consent of the Engineer. When the  use of explosives is permitted by the Engineer, blasting shall be restricted to the hours authorized  in the Engineer's written consent.  With reference to the Regulation on "Environmental Noise Evaluation and Management  (2002/49/EC)"(7 March 2008, Official Gazette: 26809), the Contractor shall in a distance of 1 km  from the site boundaries ensure that the sound level arising from the construction of building does  not exceed L $_{day}$ (dBA): 70 and from the road construction L $_{day}$ (dBA): 75. For strokes the noise  level shall in a distance of 100 m from the site boundaries not exceed LC$_{max}$:100 dBC.  The Contractor shall take all steps necessary to minimize vibration caused by plant and machinery  used on the site. No machine shall be permitted, which uses a system of dropping a heavy weight,  whether power assisted or by gravity, for the purpose of breaking up paving or foundations. Vibrations shall be monitored by vibrometer where instructed by the Engineer. Vibrations  associated with mechanical plant shall not exceed 2.5 mm/sec. as peak particle velocity in any  perpendicular direction at the site boundary.  4.7.3 Vibration during Construction  4_Vol3_d4.3_Section 4 General Requirements_en_GIR_rev6 