Zhè / xiàng / gōng / chéng / jiāng / gǎi / shàn / lǎo / chéng / qū / de / wèi / shēng / xià / shuǐ / dào / xì / tǒng

这项工程将改善老城区的卫生下水道系统。

This project will improve the sanitary sewer system in the old urban district.