In Sweden, approximately 1.2 million permanent residents and about the same number of recreational households use private wells as their water source. This entails a significant personal responsibility for water quality. According to SGU's study of 30,000 wells, 82% of all wells have problems – either unfit water (16%) or water with remarks (66%). Only 18% have completely potable water. This page presents current statistics and important facts about well water in Sweden, based on official sources from SGU, the National Food Agency, and the Swedish Radiation Safety Authority. Learn more on our blog about well water.
Quick facts about Swedish wells
Water quality in Swedish wells
According to SGU's comprehensive study of 30,000 wells (2007-2019), only 18% have completely potable water without any remarks.
66% have water that is potable with remarks – this usually means aesthetic problems like iron stains or technical problems like limescale deposits, but can also include health-related remarks that need to be addressed.
16% have unfit water that should not be used for drinking or cooking. Of these, 8% have microbiological problems (bacteria), 7% have chemical problems (metals, nitrate, etc.), and 1% have problems of both microbiological and chemical nature.
Source: Sweden's Environmental Objectives - Good quality groundwater, based on SGU's well data
Most common problems in Swedish wells
The most common problems in Swedish wells, ranked by occurrence:
1. Bacteria (35%) – The most common problem, especially in dug wells where up to 35% have unfit water due to bacterial contamination. Caused by surface water or sewage leaking into the well. Worst during summer and after heavy rains.
2. Iron & Manganese (30%) – Very common in Sweden due to naturally high levels in the soil. Gives a metallic taste, brownish water, and orange/black stains on porcelain and laundry. Primarily an aesthetic problem, but high manganese levels can affect infants.
3. pH problems (20%) – Acidic water (low pH) is common in forested areas and can corrode copper pipes. Hard water (high pH) is common in calcareous areas and causes limescale deposits.
4. Radon (15%) – Common in rock-drilled wells in granite areas. Radon outgasses from the water into indoor air and increases the risk of lung cancer with long-term exposure.
5. Metals (10%) – Arsenic, lead, and cadmium occur naturally in some rocks but pose serious health risks even at low concentrations.
6. Fluoride (8%) – From January 2026, the limit value for fluoride has been lowered from 6.0 mg/l to 1.5 mg/l. This means that about 8% of all wells previously approved are now classified as unfit due to excessively high fluoride levels.
Aesthetic problems in well water
Many wells have aesthetic problems that are not health-hazardous but affect daily life. Iron and manganese are the most common, followed by hard water (limescale) and color/odor from humic substances.
Bacterial occurrence by well type
Dug wells have a 3.5 times higher risk of bacterial contamination compared to rock-drilled wells. This is because dug wells are shallower and more exposed to surface water.
Metals that can affect health
These metals occur naturally in Swedish bedrock but can pose serious health risks:
Lead (4.2% above limit value): Particularly dangerous for children and fetuses. Affects the nervous system and brain. Can come from both old lead pipes and naturally from bedrock. Children are especially vulnerable because lead affects brain development.
Arsenic (2.0% above limit value): Naturally found in sulfide minerals in certain rocks. Long-term intake can cause chronic health effects such as cancer, cardiovascular diseases, and skin changes. Most common in Bergslagen and certain parts of northern Sweden.
Cadmium (0.8% above limit value): Can damage kidneys, skeleton, and increase the risk of cardiovascular diseases with long-term intake. Young children and individuals with low iron levels are particularly vulnerable.
Uranium (not included in diagram): Occurs naturally in granite and can affect kidney function. Elevated levels have been observed in some municipalities in Västmanland and other areas with uranium-rich bedrock.
Fluoride in well water - New limit from 2026
From January 2026, the limit value for fluoride in drinking water has been dramatically lowered from 6.0 mg/l to 1.5 mg/l. This means that tens of thousands of wells previously approved are now classified as unfit.
8% above the limit (approx. 95,000 wells): Approximately 8% of Sweden's 1.2 million wells are above the new limit value of 1.5 mg/l and thus have unfit water. High fluoride levels are particularly risky for children as it can affect tooth development and bone mineralization.
92% below the limit: The majority of Swedish wells are below 1.5 mg/l and meet the new requirement.
Action: The most effective way to reduce fluoride is through reverse osmosis (RO filter), which can remove up to 95% of fluoride in the water.
Cost of drilling a well
The total cost for a rock-drilled well varies between SEK 60,000 - 120,000, depending on depth, ground conditions, and geographical location. The average cost is approximately SEK 90,000.
- Drilling (SEK 45,000 on average): The drilling work itself, cost per meter varies between SEK 400-800 depending on the bedrock. Deeper wells cost more.
- Pump & Installation (SEK 22,000): Submersible pump, installation work, electrical connection, and possibly automatic control.
- Pressure tank & Pipes (SEK 15,000): Pressure tank system, pipes from well to house, insulation, and stormwater drainage.
- Permit & Analysis (SEK 8,000): Notification to the municipality, initial water analysis, any permit costs.
Dug wells are often cheaper (SEK 30,000-60,000) but have a higher risk of problems and a shorter lifespan.
Well types in Sweden
Approximately 70% of wells in Sweden are rock-drilled and 30% are dug. Most new wells drilled today are rock-drilled as they provide a more stable water supply and are less susceptible to drought.
Rock-drilled wells are drilled into solid rock, usually 40-120 meters deep. They have a lower risk of bacterial contamination but a higher risk of radon and metals from the bedrock.
Dug wells are shallower (usually 3-10 meters) and dug in soil. They are much more susceptible to bacterial contamination from surface water but have a lower risk of radon. Approximately 35% of dug wells have unfit water due to bacteria.
Risk profile: Rock-drilled vs. Dug well
Dug wells have a much higher risk of bacterial contamination (65% risk compared to 15% for rock-drilled) while rock-drilled wells have a higher risk of radon (85% risk compared to 20% for dug) and metals from the bedrock.
Typical well depths
Most rock-drilled wells in Sweden are between 40-120 meters deep. The most common depth is 40-80 meters (45% of wells).
- 20-40 meters (15%): Relatively shallow rock-drilled wells. Lower drilling cost but may have a higher risk of influence from surface water and drought.
- 40-80 meters (45%): The most common depth. Balances cost against water quality and supply. Good protection against surface contamination.
- 80-120 meters (30%): Deeper wells that often provide a more stable water flow. Higher cost but better protection against surface contamination and drought.
- 120+ meters (10%): Very deep wells, often in areas with difficult geological conditions or where groundwater is deep. Highest cost but usually very good water quality and supply.
Seasonal variations in water quality
Bacterial problems vary greatly throughout the year while metal levels are relatively constant.
Summer months (June-August): Bacterial levels are highest. The combination of low groundwater levels, higher temperatures, and increased use makes wells extra vulnerable. Conduct a water analysis during the summer for the best results.
Spring (March-May): After snowmelt, bacteria can be washed into wells, especially dug wells. Groundwater levels rise, which can provide better dilution but also an increased risk of surface water intrusion.
Autumn and winter: Lowest risk of bacteria as temperatures are lower and activity in the ground decreases. Groundwater levels recover during this period.