Students collected water samples from various sources in January and May 2006 to test various physio-chemical and microbiological parameters. They found that nitrate and hardness levels were higher in the second round of testing, possibly due to agricultural runoff and increased temperature. Most samples showed coliform bacteria presence, indicating contamination from human or animal waste. Regular water quality testing is important to ensure safety for human consumption.

1. SAF(V)E WATER, SWEET LIFE COMENIUS PROJECT Water analysis results

2. On January 2006 students collected water samples and bring them to lab. Water was tested according to several parameters. Each group tested one parameter and made a report. On May 2006 students collected water samples again, at the same selected water resources. The same groups tested the same parameters.

3. Water Quality Analysis Physico-chemical Parameters : Calcium Hardness Dissolved Oxygen Sulfides Microbiological Parameters : Coliforms Undesirable substances Parameters: Nitrates

4. NITRATES (VMA: 50 mg/l) The higher results obtained in second tests may be due to agriculture uses and to the increased temperature. The water with nitrates can produce cancer, so it is important to evaluate this parameter. >5 >5 >5 May 2006 >5 4,5 4,0 January 2006 A-do-Pinto Pias Fonte dos Canos

6. HARDNESS The hardness (calcium carbonate) is a parameter that varies with time and place. The higher the hardness the higher benefits to heart diseases. 55 mg/l 70 mg/l A-do-Pinto 150 mg/l Poço do Pedro May2006 Jan2006

7. CALCIUM (VMR: 100 mg/l) Calcium is important to bones, but if too much it contributes to lack of other elements. All samples showed higher rates than 40 mg/l. 67 Pias 70 Enxoé 45 Vareta 63 90/100 May 2006 Alqueva Tap water

8. SULFIDES (VMA: 250 mg/l) We think our samples have no sulfides, and that it is positive. Hydrogen sulfide is a respiratory depressant. <1 <1 <1 May 2006 <1 <1 <1 January 2006 Vila Nova Pias Fonte dos Canos

9. DISSOLVED OXYGEN (mg/l or ppm) Some second results were lower, may be due to temperature increased and higher pollution. Oxidability is not relevant to water human consumption, but very important for life in water. 6 10 A-do-Pinto 6 12 Barragem do Enxoé 8 8 Poço dos Sopos 8 8 6 May 2006 8 8 8 January 2006 Tap water Pias Fonte dos Canos

11. COLIFORMS (not allowed in water for human consumption) Most water samples are contaminated with coliforms, a group of bacteria present in human waste, and most people drink this water without knowing that it is contaminated . + coliforms present / - coliforms absent - + + - + January 2006 + Barragem do Enxoé Ribeira de Limas Fonte da Figueira + Poço dos Sopos May 2006 Poço de Pias

12. Conclusion Water for human consumption should be tested before being drunk.