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Liffey Stream Test Results


Date: Thursday 6th Oct 2011
Weather: Overcast, no wind, air temperature 11 degrees, rain in the previous few days. Place of test: 2468453E, 5729808N Near North Belt Bridge
Test Excellent Satisfactory Unsatisfactory Results Quality
pH 7.8 6.5 - 8.9 Less than 6.5 or more than 9 6.90 Satisfactory
Conductivity (µS/cm) Less than 100 100 - 500 More than 500 263 Satisfactory
Dissolved Oxygen (mg/L)       8.20  
Oxygen Saturation (%) More than 90 80 - 90 Less than 80 72.10 Unsatisfactory
Nitrate (mg/L) Less than 0.15 0.15 - 0.5 More than 0.5 3.10 BAD Very Degraded
Phosphate (mg/L) Less than 0.01 0.01 - 0.03 More than 0.03 0.45 Unsatisfactory
Turbidity (NTU) Less than 2 2.5 More than 5 0.14 Excellent
Temperature (°C)       12.20  
Coliformes  0-50  201-600  601-2000 413 Satisfactory
E.Coli       72 Excellent
Salmonella       36 Excellent
           
Conclusions:

Overall water quality ranking using macro invertebrate indicators: medium


Overall water quality ranking:
Satisfactory
 
Additional Comments:

The Lincoln Environmental Organisation (LEO) helped by WaterWatch tested the Liffey stream on the 6th October 2011. We have been testing it for the last few years. We found that from the indicator invertebrates, the longer term water quality was “medium”, the dissolved nitrate level was 3.1mg/L which was lower than in April when it was 5.1 mg/L but it was still more than 6 times worse than unsatisfactory and the phosphate level was also was very high at 0.45 mg/L. Last year the indicator invertebrates showed the lowest number of species we had ever seen (only 2), this year in April, 6 species were found, this time, in October, 5 species were found. Note: The oxygen level depends a lot on the conditions on the day, such as how fast the water is flowing and how windy it is. Note: The E.coli count (with each colony corresponding to one bacterium in the sample) were graded using the Microbiological Water Quality Guidelines for Marine and Freshwater Recreational Areas, although only one sample was tested. Published in June 2002 by the Ministry for the Environment Manatu Mo Te Taiao PO Box 10-362, Wellington, New Zealand. Updated in June 2003. ISBN: 0-478-24091-0 ME number: 474.This document is available under publications on the Ministry for the Environment’s website: www.mfe.govt.nz E. coli is used as an indicator of contamination of drinking-water by faecal material. The Maximum allowed for E. coli is less than 1 E. coli in 100 mL of sample. Drinking-water Standards for New Zealand 2005


Date: Wednesday 11th May 2011
Weather: Overcast
Test Excellent Satisfactory Unsatisfactory Results Quality
pH 7.8 6.5 - 8.9 Less than 6.5 or more than 9 6.90 Satisfactory
Conductivity (µS/cm) Less than 100 100 - 500 More than 500 260 Satisfactory
Dissolved Oxygen (mg/L)       8.90  
Oxygen Saturation (%) More than 90 80 - 90 Less than 80 90.00 Satisfactory
Nitrate (mg/L) Less than 0.15 0.15 - 0.5 More than 0.5 5.10 BAD Very Degraded
Phosphate (mg/L) Less than 0.01 0.01 - 0.03 More than 0.03 0.05 Unsatisfactory
Turbidity (NTU) Less than 2 2.5 More than 5 0.00 Excellent
Temperature (°C)       14.70  
Coliformes  0-50  201-600  601-2000 138 Excellent
E.Coli       13 Excellent
Salmonella       13 Excellent
           
Conclusions:

The Lincoln Environmental Organisation (LEO) helped by WaterWatch tested the Liffey stream on the 11th April. We have been testing it for the last few years. We found that from the indicator invertebrates, the water was “good”, as were most of the indicators, which was quite a difference form previous years. This might have been due to no recent rain and to the fact the sampling was done near a spring. However the dissolved nitrate level was 5.1 mg/L which is more than 10 times worse than unsatisfactory and the phosphate level was also was very high at 0.05 mg/L. The coli count was the lowest we have ever found it at 137.5 CFU’s per 100mL. Last year the results were 3281 CFU’s per 100mL, where over 2000 is counted as degraded.


Overall water quality ranking:
Satisfactory
 
Additional Comments:

Last year the indicator invertebrates showed the lowest number of species we had ever seen (only 2), this year 6 species were found.


Date: Monday 3rd May 2010
Weather: Overcast, no wind, There had been below average rain all summer, and no recent rain.
Test Excellent Satisfactory Unsatisfactory Results Quality
pH 7.8 6.5 - 8.9 Less than 6.5 or more than 9 6.80 Satisfactory
Conductivity (µS/cm) Less than 100 100 - 500 More than 500 303 Satisfactory
Dissolved Oxygen (mg/L)       7.36  
Oxygen Saturation (%) More than 90 80 - 90 Less than 80 69.90 Unsatisfactory
Nitrate (mg/L) Less than 0.15 0.15 - 0.5 More than 0.5 4.90 BAD Very Degraded
Phosphate (mg/L) Less than 0.01 0.01 - 0.03 More than 0.03 0.15 Unsatisfactory
Turbidity (NTU) Less than 2 2.5 More than 5 7.89 Unsatisfactory
Temperature (°C)       12.80  
Coliformes  0-50  201-600  601-2000 3281 Degraded
E.Coli       24 Excellent
Salmonella       19 Excellent
           
Conclusions:

The Lincoln Environmental Organisation (LEO) helped by LET and WaterWatch tested the Liffey stream on the 3rd May 2010. We have been testing it for the last few years. We found that from the indicator invertebrates, the water was “degraded”, the Dissolved Oxygen was only 69.9% which is “unsatisfactory”, the dissolved nitrate level was 4.0 mg/L which is 10 times worse than unsatisfactory, the dissolved phosphate levels were 0.15mg/L (anything higher than 0.5 is unsatisfactory).

The coli count was 3281 CFU’s per 100mL, where over 2000 is counted as degraded, however the count of E.coli and salmonella was very low, which was unusual, as it is usually high. This was probably because it has been very dry with no water runoff. The water in the stream would have come from the springs.

The indicator invertebrates showed the lowest number of species we had ever seen (only 2)


Overall water quality ranking:
Degraded Poor
 
Additional Comments:



Date: Saturday 4th Apr 2009
Weather: Fine with a light NE wind
Test Excellent Satisfactory Unsatisfactory Results Quality
pH 7.8 6.5 - 8.9 Less than 6.5 or more than 9 6.80 Satisfactory
Conductivity (µS/cm) Less than 100 100 - 500 More than 500 303 Satisfactory
Dissolved Oxygen (mg/L)       8.47  
Oxygen Saturation (%) More than 90 80 - 90 Less than 80 77.50 Unsatisfactory
Nitrate (mg/L) Less than 0.15 0.15 - 0.5 More than 0.5 7.00 BAD Very Degraded
Phosphate (mg/L) Less than 0.01 0.01 - 0.03 More than 0.03 0.04 Unsatisfactory
Turbidity (NTU) Less than 2 2.5 More than 5 2.98 Satisfactory
Temperature (°C)       14.80  
Coliformes  0-50  201-600  601-2000 0 Not Tested
E.Coli       0 Not Tested
Salmonella       0 Not Tested
           
Conclusions:

Aquatic invertrabrates: Pollution tolerance rating: Poor

These results could point to the spring discharge coming from a shallow aquifer. As the nitrate levels from deeper wells are nowhere near this level.


Overall water quality ranking:
Degraded Poor
 
Additional Comments:



Date: Thursday 13th Nov 2008
Weather: Fine with light NE wind, no rainfall at least week before if not longer.
Test Excellent Satisfactory Unsatisfactory Results Quality
pH 7.8 6.5 - 8.9 Less than 6.5 or more than 9 7.00 Satisfactory
Conductivity (µS/cm) Less than 100 100 - 500 More than 500 230 Satisfactory
Dissolved Oxygen (mg/L)       7.90  
Oxygen Saturation (%) More than 90 80 - 90 Less than 80 77.50 Unsatisfactory
Nitrate (mg/L) Less than 0.15 0.15 - 0.5 More than 0.5 2.00 BAD Very Degraded
Phosphate (mg/L) Less than 0.01 0.01 - 0.03 More than 0.03 0.37 Unsatisfactory
Turbidity (NTU) Less than 2 2.5 More than 5 2.00 Satisfactory
Temperature (°C)       14.50  
Coliformes  0-50  201-600  601-2000 1400 Unsatisfactory
E.Coli       885 Excellent
Salmonella       77 Excellent
           
Conclusions:

Aquatic invertrabrates used as environmental indicators:

Most dominant group: amphipods - Tolerance rating = Medium
Next most dominant group: segmented worms - Tolerance rating = Low


Overall water quality ranking:
Degraded Poor
 
Additional Comments:

As we have found last year a big increase in the nitrate levels from the small spring !


Date: Tuesday 22nd Apr 2008
Weather: Chilly southerly, fine with some cloud. Rained recently
Test Excellent Satisfactory Unsatisfactory Results Quality
pH 7.8 6.5 - 8.9 Less than 6.5 or more than 9 7.20 Satisfactory
Conductivity (µS/cm) Less than 100 100 - 500 More than 500 100 Satisfactory
Dissolved Oxygen (mg/L)       8.64  
Oxygen Saturation (%) More than 90 80 - 90 Less than 80 78.30 Unsatisfactory
Nitrate (mg/L) Less than 0.15 0.15 - 0.5 More than 0.5 1.00 Unsatisfactory degraded
Phosphate (mg/L) Less than 0.01 0.01 - 0.03 More than 0.03 0.04 Unsatisfactory
Turbidity (NTU) Less than 2 2.5 More than 5 12.00 Unsatisfactory
Temperature (°C)       10.60  
Coliformes  0-50  201-600  601-2000 1400 Unsatisfactory
E.Coli       885 Excellent
Salmonella       77 Excellent
           
Conclusions:

Aquatic invertrabrates used as environmental indicators:

Most dominant group: amphipods - Tolerance rating = Medium
Next most dominant group: segmented worms - Tolerance rating = Low


Overall water quality ranking:
Degraded Poor
 
Additional Comments:

The water testing was arranged as part of the Lincoln Envirotown monitoring of Lincoln township.
The equipment and expertise was supplied by Lincoln University Waterwatch team run by Kelvin Nicolle.

Local residents, children, and visitors from Christchurch (Mr and Mrs Cargo aged 86) carried out the testing with help from the Lincoln University team and the High school LEO (Lincoln Environmental Organisation).

The results were generally very disappointing, although there was less phosphate than the previous testing, possibly because the recent rain diluted the water. The high nitrate and phosphate levels probably come from the spring water.


Date: Tuesday 7th Aug 2007
Weather: Cloudy
Test Excellent Satisfactory Unsatisfactory Results Quality
pH 7.8 6.5 - 8.9 Less than 6.5 or more than 9 6.80 Satisfactory
Conductivity (µS/cm) Less than 100 100 - 500 More than 500 187 Satisfactory
Dissolved Oxygen (mg/L)       9.30  
Oxygen Saturation (%) More than 90 80 - 90 Less than 80 87.10 Satisfactory
Nitrate (mg/L) Less than 0.15 0.15 - 0.5 More than 0.5 2.10 BAD Very Degraded
Phosphate (mg/L) Less than 0.01 0.01 - 0.03 More than 0.03 0.18 Unsatisfactory
Turbidity (NTU) Less than 2 2.5 More than 5 5.40 Unsatisfactory
Temperature (°C)       11.70  
Coliformes  0-50  201-600  601-2000 284 Satisfactory
E.Coli       157 Excellent
Salmonella       77 Excellent
           
Conclusions:

Aquatic invertrabrates used as environmental indicators:

Most dominant group: amphipods - Tolerance rating = Medium Next most dominant group: segmented worms - Tolerance rating = Low


Overall water quality ranking:
Degraded
 
Additional Comments:

There had been heavy rain the previous day before this test.