in site vs at site

Some examples from the web:

• The key factor for maintaining the population is the summer habitats, situated in the forest zone of the mountain, which are currently covered only for about 10 % of the population (only in site BG0000496).
• Declare that, in respect of the planned tourist complex Is Arenas in the Municipality of Narbolia, which concerns the habitats and species present in site ITB032228 Is Arenas:
• Target's in site, waiting for your go.
• Under EU regulations what level of consultation with local communities is necessary prior to a local authority engaging in site selection for a sewerage treatment plant or a landfill site?
• On the other hand, the update of the initial list of sites of Community importance for the Continental biogeographical region is necessary in order to reflect any changes in site related information submitted by the Member States following the adoption of the Community list.
• The financial guarantees are intuitu personae, so that in the event of a change in site operator, the French Environmental Code requires the new operator to make a statement to the relevant Prefect within one month.
• I can supervise production in Site X. Or I can man one of the teams in Manhattan.
• The pipeline will compete with the latter and the aid will distort competition with those companies that invest heavily in site selection, jetty facilities and the like.

Some examples from the web:

• I'm at site 6412-Foxtrot with Teo Braga.
• The plutonium at Site X will never be pure enough.
• Gamma sensor at Site Nine is not responding.
• But, Charlie, we're not using the plutonium at Site X.
• What you saw at Site X was a pilot plant designed to work out the kinks.
• With the plutonium that they are making at Site X,
• You at Site Nine yet?
• As at site number 119, the railway bridge and electricity station at Cloudheath, Suffolk, where Tulse Luper says the information on signs is significant.
• That is why all EMAS registered organisations should report on core indicators at site level, though the regulation does not explicitly require this.
• "at site, bring cash, no cameras."
• Has no one at site abandoned?
• In any case, information on trends in emissions to air and water, water consumption, use of energy and the amount of waste should be provided at site level.
• time course of onset and signs of toxicity, including dermal irritation at site of administration, if any, for each animal;
• The establishment, at site level, of the conservation objectives, as well as of the appropriate conservation measures aiming at maintaining or restoring the habitats and species of Community interest at a favourable conservation status falls under the full responsibility of the national competent authorities.
• We've had static at Site Nine all day.
• I spent three years at Site X.
• Gentlemen, we've just gotten word that more than a gram of plutonium will be shipping imminently from the graphite reactor at Site X.
• Director of Operations at Site X. He says he needs to speak with you immediately.
• There's a mobile link up at Site 26 we can work out of, way up in the mountains.
• The workers at Site X barely know what they're making down there much less what it's used for.