Springs in the Central Parts of Vallentuna Municipality Traditions and Threats
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DEGREE PROJECT IN CHEMICAL ENGINEERING AND TECHNOLOGY, FIRST LEVEL STOCKHOLM, SWEDEN 2017 Springs in the central parts of Vallentuna municipality Traditions and threats Hannan Hadodo A stream emerging from a spring horizon in Arkels tingstad, Vallentuna KTH ROYAL INSTITUTE OF TECHNOLOGY KTH CHEMICAL SCIENCE AND ENGINEERING Degree Project Bachelor of Science in Chemical Engineering and Technology Title: Springs in the central parts of Vallentuna municipality traditions and threats Swedish title: Källor i centrala Vallentuna traditioner och hot Keywords: Spring, water quality, restoration Workplace: KTH and Vallentuna References in Vallentuna: Anton Mankesjö, Vallentuna kommun Staffan Rosander, Vallentuna Hembygdsförening Anders Eriksson, Källakademin Nicole Sundin, Vallentuna kommun Supervisor: Olle Wahlberg Student: Hannan Hadodo Date: 2017-11-07 Examiner: Lars Kloo 2 Abstract Twenty springs in the central parts of Vallentuna municipality have been studied to determine their present water qualities and suggest actions that could be taken to improve the water quality and availability of the springs. The measured parameters are the water volume, the water flow, the water temperature, the pH-value, the electrical conductivity, the chloride concentration, the alkalinity and the CODMn. The sensory properties of the springs were also examined, which include odour, colour, clarity and precipitation. Measurements of the water flows, the water temperatures, the pH-values and the electrical conductivities were performed during a field trip in Vallentuna. During this field trip, two water samples were taken from each spring. Thereafter, the alkalinity, the chloride concentration, the CODMn and the sensory properties were determined in the laboratory. Four of the springs, which were wells, have water of high quality and can easily be restored. Some of the twenty springs have not been cared for or have even disappeared. The water from the spring horizon near Arkels tingstad is unfortunately mixed with stormwater, which runs off the nearby roads. This contamination is examined by measuring the chloride flows of the different streams. The roads also contribute with metal pollution, with metals such as cadmium. Therefore, metal speciations of cadmium were examined. A simple solution is suggested to remove the metal pollution. The measured water flows of all of the spring waters in Vallentuna were quite small. The results of the measurements of the spring waters were compared with the values recommended by Livsmedelsverket and Socialstyrelsen. Most of the values were between the recommended limits for drinking water. Suggestions are given to improve the springs concerning water quality and availability. 3 Sammanfattning (Abstract in Swedish) Tjugo källor i centrala Vallentuna studerades för att bestämma deras vattenkvalitet och för att föreslå åtgärder i avsikt att förbättra vattenkvaliteten och tillgängligheten av källorna. De mätta parametrarna är vattenvolym, flödeshastighet, vattentemperatur, pH-värde, elektrisk konduktivitet, kloridkoncentration, alkalinitet och CODMn. Dessutom undersöktes källvattnens sensoriska egenskaper, vilka innefattar lukt, färg, klarhet och utfällning. Mätningar av flödeshastigheterna, vattentemperaturerna, pH-värdena och elektriska konduktiviteterna gjordes under en exkursion i Vallentuna. Två vattenprover togs från varje källa. Därefter undersöktes kloridkoncentrationen, alkaliniteten, CODMn och de sensoriska egenskaperna på laboratoriet. Fyra av källorna, vilka var brunnar, har vatten av hög kvalitet och kan relativt enkelt restaureras. En del av de tjugo källorna har inte vårdats under lång tid och har till och med försvunnit. Vattnet från källhorisonten vid Arkels tingstad har olyckligtvis blandats med dagvatten, vilket rinner från de närliggande vägarna. Denna förorening analyseras genom att mäta kloridflödet i olika strömmar. Vägarna bidrar också med metallföroreningar, t.ex. kadmium. Därför har också metallförekomstformer för kadmium modellerats. En enkel metod föreslås för att avlägsna metallföroreningarna. Vattenflödena från källorna i centrala Vallentuna är relativt små. Resultatet av mätningarna av källvattnen jämfördes med de rekommenderade värdena för dricksvatten enligt Livsmedelsverket och Socialstyrelsen. De flesta värdena låg inom gränserna för de rekommenderade värdena för dricksvatten. Förslag ges till förbättring av källorna med avseende på vattenkvalitet och tillgänglighet. 4 Preface During my degree project, I have learnt to appreciate the value that springs have to us humans. Exploring different locations in nature that are not commonly visited and finding clean spring water was a new experience for me. It shows how we tend to forget that clean water can be accessed not only from water taps, but also from other sources such as wells. Maintenance of spring water gives the opportunity for future generations to enjoy clean water from such sources. I would like to express my sincere thanks to my supervisor at KTH Olle Wahlberg, who came up with my degree project about the springs in Vallentuna. Olle Wahlberg guided and helped me during the course of my degree project. I also wish to thank residents in Vallentuna who gave information about some of the springs, and Källakademin that has expressed interest in my work. 5 Table of Contents Abstract 3 Sammanfattning (Abstract in Swedish) 4 Preface 5 1 Introduction 8 1.1 Problem 8 1.2 Goal 8 1.2.1 Methods 8 1.3 Aim 8 1.4 Limitations 8 2 Background 10 2.1 Traditions and importance of springs in Vallentuna 10 2.2 Threats to springs in Vallentuna 11 2.3 Water properties 11 2.3.1 Electrical conductivity 11 2.3.2 Chloride 12 2.3.3 pH 12 2.3.4 Alkalinity 12 2.3.5 COD 12 2.4 Solutions for problems with the water quality of springs and wells 12 3 A survey of the studied springs 14 3.1 Springs in area A 15 3.1.1 A1 Kyrkans källa 15 3.1.2 A2 Prästgårdens källa 15 3.1.3 A3 Kullens källa 15 3.1.4 A4 Spring in Åby gård 16 3.1.5 A5 Well in Åbyholm 16 3.2 Springs in area B 16 3.2.1 B1 Well close to the spring horizon 16 3.2.2 B2 Stormwater stream from Skadronvägen 17 3.2.3 B3 Stormwater stream 17 3.2.4 B4 Stream in Arkels tingstad 17 3.2.5 B5 Stream in Hasseludden 18 3.2.6 B6 Spring near Uthamravägen 18 3.3 Springs in area C 18 3.3.1 C1 Well near the brewery house/ washhouse 18 3.3.2 C2 Well near a cow stable of Uthamragård 19 3.3.3 C3 Spring near the main building 19 3.3.4 C4 Old basin used for washing clothes 19 3.3.5 C5 A crofter’s well 19 3.4 Springs in area D 19 3.4.1 D1 Well in a forest 20 3.4.2 D2 Well in a garden 20 3.4.3 D3 Old construction for washing clothes 20 3.4.4 D4 Spring found in the SGU database 20 3.4.5 D5 Deeply drilled well 21 4 Laboratory Methods 22 4.1 Determination of the chloride concentration 22 4.2 Determination of the alkalinity 22 4.3 Determination of the CODMn 23 6 5 Experiments 25 5.1 Field trip 25 5.2 Sensory properties 25 5.3 Laboratory methods 25 5.3.1 Chloride concentration 25 5.3.2 Alkalinity 26 5.3.3 CODMn 26 6 The chloride flow in Arkels tingstad 27 7 Different forms of metal ions 28 8 Results 29 8.1 Physical-chemical properties of the spring waters 29 8.1.1 Volume of the spring water in the wells 29 8.1.2 Water flow of the streams 29 8.1.3 Water temperature 30 8.1.4 pH-value 30 8.1.5 Electrical conductivity 31 8.1.6 Chloride concentration 31 8.1.7 Alkalinity 32 8.1.8 CODMn 32 8.2 Sensory properties 33 8.3 Chloride flow of Arkels tingstad 33 8.4 Speciation of metal ions 33 9 Discussion 34 9.1 Properties of the springs 34 9.2 Water quality of the springs 34 9.3 Human influence 35 9.4 Improvement of the water quality 35 10 Conclusions 36 11 Bibliography 37 Appendix 1: Images of the spring water samples 39 Appendix 2: Co-ordinates of the springs 41 Appendix 3: Calculations of the water volume and water flow 42 Appendix 4: Laboratory results 43 Appendix 5: Calculations for the analysis methods 44 Appendix 6: Calculations for the chloride flow in Arkels tingstad 45 Appendix 7: Physical-chemical properties measured in the field trip 49 Appendix 8: Physical-chemical properties measured with laboratory methods 50 Appendix 9: Sensory properties of the water samples 51 7 1 Introduction Vallentuna municipality is located 25 km north of Stockholm centre. Today it is a suburb of Stockholm. There are many springs in Vallentuna that were earlier used as water supplies. Most of these springs are now forgotten or have been contaminated. Some of them have even disappeared. Most people in Vallentuna now use tap water from Mälaren. Some springs can still be restored and enjoyed by people who visit. The springs also have a cultural value, and every courtyard in Vallentuna once used to have its own spring or well. Twenty springs in central Vallentuna are studied in this project. A few of the springs are well cared for, but most of them are forgotten and not maintained. However, the springs are an example of local traditions and the threat to this cultural heritage that the expansion of the modern society leads to. In Vallentuna, the spring water mostly comes from small moraine hills, which is the reason why the water flow is usually small. The ground water influences the water quality of the springs and therefore, the springs have been used to survey the ground water quality by SGU (The Swedish Geological survey). 1.1 Problem Many of the springs in the central parts of Vallentuna municipality are no longer in use. These springs have a potential to be used for drinking water if they meet the requirements for drinking water.