River Taf Water testing results-April 26

Based on the data for the River Taf in April 2026, the situation is significantly more extreme than in the smaller tributaries. While the Nitrate levels are lower, the pH levels have reached a critical and potentially dangerous stage.

Here is the breakdown of the April 26 results for the three main Taf sites (Llandowror, Whitland Church, and the Water Monitoring Station):

1. Critical pH Readings (The Primary Concern)

This is the most alarming part of the Taf data. The pH has moved beyond "high" and into the harmful/hazardous range:

• Llandowror: 8.8

• Whitland Church: 9.5

• Water Monitoring Station: 9.7

Conclusion: At pH 9.5 and 9.7, the water is becoming chemically aggressive. This level of alkalinity can cause physical damage to the skin and gills of fish and is often lethal to many macroinvertebrates. Since your ammonia is zero, you are avoiding "Ammonia Toxicity" for now, but the pH alone is a major stressor.

2. Evidence of Intense Biological "Overdrive"

The combination of your DO and pH confirms that the river is in a state of intense daytime photosynthesis:

• Dissolved Oxygen (DO): 11.3 to 11.7 mg/L.

• Water Temp: 10.5°C to 11.3°C.

• Interpretation: At 11°C, "100% saturation" is approximately 11.0 mg/L. Your readings of 11.7 mg/L indicate the water is supersaturated. The algae and diatoms are pumping out so much oxygen during the day that the water literally cannot hold any more.

3. The Phosphate "Turbo-Charger"

While Nitrates in the Taf are moderate (1.2–2.6 mg/L), the Phosphate level at the Water Monitoring Station is very high at 0.45 mg/L.

• Conclusion: This high phosphate is likely the "limiting nutrient" that has triggered the massive pH spike. It is providing the fuel for the "blanket weed" you observed in the low-water margins.

4. Why the Taf looks "Clear" but is Chemically Volatile

• Ammonia: 0.00 to 0.01 mg/L.

• Conclusion: The absence of ammonia and the high clarity suggest that this isn't a "fresh" slurry dump. Instead, the river is reacting to the dissolved nutrients that have leached into the system over the last few months. The "Invisible" pollution we discussed earlier is at its peak here.

Summary Table: River Taf (April 26)

Site	pH	Nitrate (mg/L)	Phosphate (mg/L)	DO (mg/L)
Llandowror	8.8	2.2	0.09	11.3
Whitland Church	9.5	1.2	0.13	11.5
Monitoring Stn	9.7	2.6	0.45	11.7

Final Verdict for the Taf:

The River Taf is currently experiencing a major alkaline event. The pH of 9.7 at the Monitoring Station is exceptionally high for a natural river system and indicates that the nutrient loading (specifically Phosphates) has pushed the biological productivity of the river into a dangerous "hyper-active" state.

Recommendation: If you have the ability to test at night or very early morning (dawn), you will likely see these numbers invert—the pH will drop, but the Oxygen might crash as the algae switch from producing oxygen to consuming it. This "diurnal swing" is what ultimately kills fish in high-nutrient rivers.