Often overlooked yet incredibly vital, groundwater plays a crucial role in our water systems. Unlike surface water, visible in rivers, lakes and reservoirs, groundwater exists below our feet and supplies most of our drinking water. This invisible resource supplies drinking water to billions — supporting agriculture and maintaining ecosystems. This hidden treasure is especially significant in regions where surface water is scarce.
Let’s explore the importance of groundwater, global usage and the cutting-edge technologies that ensure its safety.
Groundwater vs. spring water vs. surface water
First, let’s define groundwater. By figuring out the differences between water sources, you’ll understand how they journey to our tap (and other uses).
Groundwater is water found underground, usually in aquifers. It covers all the spaces and pores in materials such as sand, gravel and other rocks, and flows like water does with sponges. It’s typically clean due to natural filtration through soil and rocks, but surface activities can contaminate it.
Spring water is a subtype of groundwater, as it’s extracted from underground sources. It’s the most popular option for bottled water since it tends to have absorbed and moved through various soil and minerals, giving it the purity often sought for drinking water.
Surface water is usually what you first think of when you think of water on earth. It’s your rivers, lakes and reservoirs. However, since it’s more easily accessible, it is also the most susceptible to contamination and usually requires extensive treatment before it’s safe for consumption.
Each source has advantages, but groundwater stands out for its natural purity and consistent supply.
Overview of countries using groundwater
Groundwater is a primary water source for many countries around the world. It’s an unsung hero, supporting millions, yet each country taps into this resource differently. For example:
China: groundwater is a significant source of drinking water, especially in the northern regions where surface water is limited. Unlike many energy commodities, water doesn’t have viable substitutes and is critical for growing food and generating energy — two life-critical activities for us. Their 2022 drought gave us a preview of what can come with water challenges: global food security, energy market and supply chain devastation.
India: groundwater meets about 85% of the rural drinking water needs and 50% of urban requirements. India is the biggest groundwater user, extracting more than China and the US combined. It also meets more than half of India's total requirement for clean water. 89% of groundwater is used for irrigation, 9% for the household and 2% for industry. Consider that the population boom has depleted almost every city and village's wetlands, water bodies and rivers.
The Netherlands: known for its minimal use of chlorine, this country primarily relies on groundwater for its clean water needs. It uses the best source available, usually microbiologically safe groundwater, prefers physical process treatments and monitors for timely detection of system failures to prevent significant health consequences.
Switzerland: like the Netherlands, Switzerland often uses groundwater without chlorine disinfection, leveraging natural filtration processes. However, in the last 50 years, one in three water supplies in Switzerland has closed a water catchment due to use conflicts. These tend to come from housing construction and agriculture, especially rezoning issues.
Spain, France and the UK: these countries mandate the use of chlorine for disinfection, ensuring microbial safety but sometimes affecting taste. For instance, chlorine levels in England and Wales are very low compared to other countries where water companies use 0.5 mg/l or less chlorine. In France, 95% of people are supplied with chlorinated tap water. Geographical inequalities remain due to the type of resources operated. In Spain, while almost all public tap water is safe to drink, there are various issues with the taste, odour, chlorine by-products, microplastics and local pipe contaminations.
The US: approximately 50% of the population uses groundwater for domestic purposes. It’s used for drinking water, irrigation, industry and livestock. States like California and Florida depend heavily on groundwater, since they receive little precipitation, have limited surface water resources and are highly dependent on agriculture and growing populations.
As we can see, groundwater is a local resource and a global necessity that shapes water management strategies across continents.
BactoSense: enhancing groundwater monitoring
Technology plays a key role in obtaining high-quality, safe groundwater. Despite its relative safety, groundwater faces risks of contamination from surface water. Advanced monitoring technologies like BactoSense are crucial for understanding its quality. BactoSense offers real-time monitoring of microbial levels in water, providing actionable insights in a fully automated way.
The technology used is a game changer for chlorinated and non-chlorinated water systems. In the UK, where chlorination is standard, BactoSense assists Quality Assurance (QA) Managers in water plants to fine-tune their treatment processes, ensuring compliance with strict regulations set by authorities like OFWAT. In countries like the Netherlands, BactoSense acts as a watchdog, helping QA Managers monitor the natural filtration process and ensure that safe, high-quality water is consistently delivered without chlorine.
By providing rapid, detailed analysis, BactoSense empowers water managers to make informed decisions, ensuring the safety and quality of our groundwater resources.
Use cases of BactoSense in groundwater management
Thanks to advanced flow cytometry, BactoSense allows for precise tracking of microbial populations, offering critical insights into how groundwater quality evolves. This technology is particularly valuable in managing groundwater catchments. For instance, Veitur uses BactoSense data in Iceland to refine and extend the catchment periods of wells, optimising water delivery and ensuring that only water meeting microbiological key performance indicators enters the treatment process. Additional applications are borehole qualification and characterisation, which are done by comparing microbiological quality across different boreholes over time. This ensures only the best-performing boreholes are used, enhancing overall water quality and production capacity.
In Switzerland, a local utility uses BactoSense to monitor the quality of groundwater after river water infiltration. The system determines safe catchment windows, especially after heavy rains, when surface water can break through and contaminate the groundwater. Water utilities can better characterise and survey catchment sites by understanding the impact factors like seasonality, extreme weather, or seismic events on groundwater quality. For example, in a flooding event in the Swiss capital of Bern, BactoSense detected significant changes in groundwater quality, leading to a 10-day impairment.
BactoSense also supports on-demand disinfection, safeguarding public health when water quality deteriorates. In the Swiss community of Saxon, PMAX, a local engineering firm, used BactoSense data to trigger a multi-level response. This included mild chlorination, frequent monitoring when conditions deteriorated, and stronger measures, including alternative water supplies, when quality severely declined.
Finally, BactoSense enables event-based sampling, allowing utilities to take lab samples immediately after detecting abnormal changes in water quality. Thus, quicker responses and enhanced consumer safety are ensured.
Tapping into a sustainable future
Groundwater is a vital resource that supports millions worldwide. From rural wells to sophisticated water systems, groundwater plays a crucial role in our daily lives. Management and monitoring are critical to ensuring a safe and sustainable water supply.
The diverse groundwater management and disinfection approaches highlight the need for tailored, sustainable solutions. As we face challenges like climate change and population growth, innovative technologies like BactoSense become increasingly vital.
By understanding and protecting our groundwater resources, we’re safeguarding our water supply and investing in the health and sustainability of our planet. Let’s cherish this hidden treasure and ensure its continued flow for generations.
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