SUMMARY OF THE TEST REPORT

Executive summary

• Multiple samples analyzed for drinking water quality and RO plant treated outputs (RO water, plant-2, plant-1, STP treated water, etc.).
• Overall, several samples comply with IS 10500:2012 drinking water standards, while others show partial or full non-compliance (notably residual chlorine, certain hardness parameters, silica, and some metals).
• Microbiology results consistently indicate absence of Total Coliforms and E. coli in most samples (compliance), with a few entries showing absence as per IS 10500 requirements.
• Treated water outlet parameters (pH, TDS, TSS, BOD, COD, oil & grease) show mixed results across outlets; some meet TNPCB limits, others do not.

1. Reference and general information

• Laboratory: Bio Green Lab Services (UAN TN02A0155256), ISO 9001:2015 certified.
• Sample sources: RO Water, Well Water, Life Sciences Block, Ladies Hostel, Men’s Hostel, Campus canteen, STP Treated Water, etc.
• Reporting dates span mid-August 2025.
• Agencies/standards cited: IS 10500:2012 (drinking water), APHA 23rd Edition (procedures), TNPCB/tolerances, with some methods per 2017 revision.
  
  

2. Individual sample results and compliance status

   A. RO Water – Ladies Hostel

• pH (25°C): 6.5–6.8 range observed in various entries; IS 10500 acceptable range 6.5–8.5.
• Odour: Agreeable; acceptable.
• Turbidity: Below Detection Limit (BDL) to 0.3 NTU (acceptable: ≤ 5 NTU).
• Conductivity: 70–76.9 µS/cm at 25°C (acceptable: ≤ 2500 µS/cm).
• TDS: 40–1128 mg/L across entries (varies by sample; some entries near or above 600 mg/L limit for drinking water (2000 mg/L max under IS 10500); most entries are below 600 mg/L but one shows 1128 mg/L in “TDS” for a college plant sample outlet; this may be a concern if intended as drinking water; confirm sampling point).
• Total Alkalinity as CaCO3: 12–280 mg/L (within 200–600 mg/L acceptable range varies by sample source; IS 10500 does not set strict limits for T.A. in all contexts; ensure within acceptable range per IS 10500).
• P-Alkalinity: Nil to 6.0 mg/L (Nil or low; acceptable as per IS 10500).
• Total Hardness as CaCO3: 7–14 mg/L (low hardness; acceptable).
• Calcium hardness: 4–8 mg/L; Magnesium hardness: 0–6 mg/L.
• Iron: BD L or below 1.0 mg/L (acceptable).
• Chloride: 13–29 mg/L.
• Sulphate: 4.5–11 mg/L.
• Silica (as SiO2): 1.0–1.2 mg/L.
• Free Residual Chlorine: BDL to 0.2 mg/L; some entries show Nil or BDL (acceptable if residual chlorine target is not critical for the downstream use; for drinking water, residual chlorine is typically desired; confirm local requirement).
• Remarks: Some samples “Comply with drinking water specification” while others “Does Not Comply” (notably entries of 7.0–7.4 pH, high TDS 1128 mg/L, and some residual chlorine non-detection if required). See specific notes per sample.

   B. RO Water – Ladies Well Water

• pH: 6.5–7.0 (within IS range).
• Odour: Agreeable.
• Turbidity: BD L to 0.3 NTU.
• TDS: 420–948 mg/L (varies; some samples meet ≤ 600 mg/L recommended for drinking water; others exceed).
• Alkalinity: 12–280 mg/L (as CaCO3).
• Total Hardness: 14–420 mg/L (some samples show 420 mg/L; within IS 10500’s typical hardness guidelines? IS 10500 doesn’t specify a single hard-limit; e.g., 600 mg/L as a general external guidance).
• Calcium: 4.3–114.2 mg/L.
• Magnesium: 0–140 mg/L.
• Iron: BD L–1.0 mg/L.
• Chloride: 16–29 mg/L.
• Sulphate: 7.3–98.5 mg/L.
• Free Residual Chlorine: BD L to 0.0–0.2 mg/L.

C. Microbiology – Ladies Hostel / Life Sciences Block / Other RO plant samples

• Total Coliforms: Absent in all listed entries (compliant with IS 10500:2012).
• E. coli: Absent (compliant).
• Remarks consistently indicate compliance for the tested provisions.

D.  Treated Water Outputs (Outlets)

• College Plant (Treated Outlet): pH around 7.6–7.7; TDS 1028–1128 mg/L; TSS BD L; BOD 3.0–3.5 mg/L; COD 17–19 mg/L; Oil & Grease BD L.

• • TNPCB drinking water limits are not explicitly cited here, but high TDS (1128 mg/L) may exceed typical drinking water recommendations (IS 10500 provides guidance; often aims for <= 1000 mg/L). The BOD/COD values appear reasonable.

• STP Treated Water: pH 7.63–7.71; TDS 1028–1128 mg/L; TSS BD L; BOD 3.0–3.5 mg/L; COD 17–19 mg/L; Oil & Grease BD L.

• • Non-compliance noted for some samples (the August 16, 2025 report indicates “Not Comply with drinking water specification as per IS:10500:2012” for some parameters). In the “Treated Outlet as per TNPCB” table, pH within range; TDS and other parameters may require monitoring.

E. Campus Canteen / Well Water samples

• Turbidity in canteen/well water samples generally within acceptable limits (BDL to 1.2 NTU).
• TDS ranges 38–898 mg/L depending on the source/outlet; some high values observed (e.g., 898 mg/L).
• Chloride: 13–241 mg/L.
• Sulphate: 4.5–153 mg/L.
• Free Residual Chlorine: BD L to Nil (acceptable in distribution systems where chlorine is not required for non-potable uses; for drinking water, residual chlorine is typically desired).
• Total Iron: 0.1–1.89 mg/L (some samples exceed 1.0 mg/L; IS 10500 allows up to 0.3 mg/L for iron? Actually IS 10500 does not specify a strict mg/L limit for iron; many guidelines cite 0.3 mg/L as a limit for iron in drinking water; however the IS 10500 standard for iron is 0.3 mg/L? The data here uses “1.0” as a test method standard; please verify local limit if needed.)
• Calcium/Magnesium: within typical ranges in most entries, some values show magnesium up to 150 mg/L.

F. PM: STP Treated Water

• pH around 7.63–7.71; TDS around 1028–1128 mg/L; BOD 3.0–3.5 mg/L; COD 17–19 mg/L; Oil & Grease BD L; Silica ~12–15.9 mg/L; Free Chlorine BD L or Nil.

3. Observations and potential issues

• TDS variability is significant across samples, with several readings well above 600 mg/L (some up to ~1128 mg/L). IS 10500 allows general use drinking water with TDS values typically acceptable up to around 1000 mg/L, but the precise limit depends on use and local norms. Consider post-treatment polishing or source evaluation if drinking water usage is intended for those higher-TDS samples.
• Free residual chlorine is often BD L or very low. If disinfection residual is required for safety, ensure that chlorination is maintained at recommended levels (commonly 0.2–0.5 mg/L) in distribution points.
• For some samples, Calcium Hardness and Magnesium Hardness values are relatively high (e.g., Calcium hardness 60–110 mg/L in some lines; Magnesium hardness up to 150 mg/L). While not always disqualifying, elevated hardness may affect taste/softness and scaling. Consider water softening if softness is required for specific processes or consumer acceptance.
• Iron levels in some samples are BD L to 1.89 mg/L; if IS 10500 is applied strictly, iron limit is around 0.3 mg/L (check latest local limit). If used for drinking water, consider iron removal (filtration/oxidation) where needed.

4. Recommendations

• For drinking water outlets showing higher TDS (e.g., > 1000 mg/L), assess source water quality and consider post-treatment steps such as reverse osmosis polishing, ion exchange, or blending with lower-TDS sources to meet recommended drinking water standards.
• Ensure residual chlorine distribution targets are met for safety, particularly at service taps. Regular monitoring and adjustment of disinfection dosing.
• Implement routine microbiological checks (as already performed) with a frequency aligned to supply reliability and occupancy; maintain zero total coliforms and E. coli per IS 10500.
• Review hardness and mineral balance for processes or consumer preference; if taste/scale is an issue, consider softening or remineralization steps as appropriate.
• Maintain documentation of sampling points and ensure samples are taken consistently at representative points (e.g., post-RO output, distribution taps, well water upstream of treatment, etc.)