According to ASM Handbook Vol. 13B (Corrosion: Materials), the recommended maximum chloride level for 316/316L alloys in water systems at ambient temperature is 1000 ppm. However, the suitability of 316 stainless steel in your application will depend not just on the level of chlorides, but what other constituents are present and at what levels, what the normal and maximum operating temperatures are, the degree of aeration, etc.