I need help with proofreading this translation (spa>eng)
I got this text which i translated from Spanish to English (inverse translation, in my case) which is a sort of trial for me to get an in-house job. It's just one page. The only problem is that i'm not a native speaker of English and, though I tried my best, I need someobody that could help me doing proofreading (just for the sake of help). If it's needed I got the original, just ask me about it. Thanks in advance!
[It will be developed in a timely manner and according to the stipulated requirements by the schedule, plan and proceedings in order to carry out the operations of pre-commissioning, commissioning, start-up, operation and behavior tests at the facilities of project CCC La Mesilla II.
Prior to the preceding operations, a verifying protocol for the non-existence of unsafe conditions will be implemented, just as fulfill the requirements in terms of environmental protection that current legislation demands, in compliance with the specifications of this project.
Implementation plan of commissioning and start-up is defined in accordance to the completion date of CCC North II project, for which the activities of commissioning and start-up will be put in place, as indicated in compliance with the next sequence:
• Precommisioning and Mechanical Completion • Commisioning and Start-Up tests, as indicated in section 3.9.1.2 • Functional tests, as indicated in section 3.9.1.2.1 • Behaviour tests, as indicated in section 3.9.1.2.2 • Emission tests, as indicated in section 3.9.1.2.2
1.1 BIDDING PURPOSE The purpose of this international public bidding is the award for a financed civil cost plus construction work contract to carry out the project of funded inversion, which is described below.
[…]
1.4.1 Every person or group of persons that based on the aforementioned submits a proposal (a “Bidder”) will be responsible for the fulfillment of all its specifications as requested by the official announcement, in the understanding that Bidders will only submit one proposal to each contract proceeding; once the official presentation and opening of proposal is started, none of them would be withdraw or leave without effect by Bidders request.
This bidding is not opened to natural or artificial persons disqualified by a resolution of the Ministry of Public Service, in the terms of Public Works and Related Services Law or Act on Acquisition, Leasing and Public Sector Services.] 
1 Answer
First of all, for not being a native speaker you write english impeccably well! There were only a few areas with minor concerns that can be easily fixed. I was not sure what exactly you meant so i gave you options. I hope this helps!
"Prior to the preceding operations, a verifying protocol for the non-existence of unsafe conditions will be implemented, (just as fulfill the requirements) in terms of environmental protection that current legislation demands, in compliance with the specifications of this project."
The part in side (...) does not make sense and I cannot tell what you are trying to say. You could possibly mean (just fulfill the requirements) or (just as the fulfilled requirements)
"1.4.1 Every person or group of persons( that based on the aforementioned) submits a proposal (a “Bidder”) will be responsible for the fulfillment of all its specifications as requested by the official announcement, in the understanding that Bidders will only submit one proposal to each contract proceeding; once the official presentation and opening of proposal is started, none of them would (be withdraw or leave without effect by Bidders request)."
The part in side (...) should be (that is based on the aforementioned) and (be able to withdraw or leave without the Bidders request) or (be able to withdraw or leave with effect by the Bidders request)
