Sewage and waste disposal is properly plumbed from the facility and does not provide a potential source of contamination to contact surfaces, products, components, water supplies, etc.

污水与废弃物通过工厂管道正确排放，不能成为接触面，产品，原料与供应水的潜在污染源。

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He said investigators were working under the "thesis" that the Daschle letter was the source of contamination among the postal workers.

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In any event, the presence of mouse DNA in these cells must be considered as the source of contamination reported in this experiment.

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Although ice can become contaminated, researchers ruled it out as the source of contamination after testing revealed that it did not contain coliform bacteria.

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