Chloride limit in treated potable water (public supplies): What is the maximum permissible chloride content that should not be exceeded in treated water supplied to the public (expressed as mg/L or PPM)?

Introduction / Context:Chloride in drinking water is primarily an aesthetic parameter affecting taste and potential corrosion behavior. Standards specify desirable or permissible limits to ensure consumer acceptability and long-term system integrity. Engineers should know common reference values used in design and compliance checks.

Given Data / Assumptions:

• Treated water distributed for public consumption.
• Chloride expressed as mg/L (PPM).
• Typical Indian/International guideline band for taste acceptability.

Concept / Approach:Many standards list a desirable limit around 200–250 mg/L for chloride due to taste thresholds, with a higher permissible limit in the absence of an alternative source. In textbook multiple-choice contexts for public water supplies, 250 mg/L (PPM) is the widely cited ceiling for acceptability.

Step-by-Step Solution:Identify parameter: chloride concentration in finished water.Recall common acceptability limit: approximately 250 mg/L.Select the option matching 250 PPM.

Verification / Alternative check:Consumer taste panels and long-standing guideline values correlate noticeable salty taste increases above roughly 250 mg/L, supporting this benchmark for municipal supplies.

Why Other Options Are Wrong:

• 50–200 PPM: within acceptable range; not the typical maximum cited for public supplies.
• Values below 250 PPM are often desirable, but the question asks for the maximum permissible limit.

Common Pitfalls:

• Confusing chloride with residual chlorine (used for disinfection and measured in mg/L but at far lower levels).
• Assuming 250 PPM is a health-based limit; it is primarily aesthetic.

Final Answer:250 PPM