Turning on the tap for a refreshing glass of water might seem to be something most people should be able to take for granted.
But what if that water makes you sick?
An overhaul of drinking water regulations and monitoring is under way this year, which will benefit rural populations.
Untreated water used for drinking can contain bacteria or protozoa that can cause illness, particularly in rural communities that rely on tank water or water drawn from streams.
According to Northland District Health Board health protection officer Keith Turner, about 40 per cent, or 73,500 people, in Northland get their water from sources other than reticulated systems.
The board keeps a database of enteric diseases notified to the medical officer of health and the most recent records showing 139 cases of gastric illnesses between March 2019 and March 2020 where the main risk of infection appeared to be related to drinking or using untreated water for domestic purposes.
Many cases of a "tummy bug" may never be reported to the DHB so the numbers are likely to be much higher.
Forty cases were in the Far North, 29 in Kaipara and 70 in the Whangārei district.
The waterborne illnesses include the gut-churning campylobacteriosis, cryptosporidiosis, gastroenteritis, giardiasis, paratyphoid fever, salmonellosis and yersiniosis.
Pathogens (disease-causing micro-organisms) can contaminate roof and tank water supplies, especially from birds and animals that poop on the roof or whose bodies end up being washed into the water tank.
Bacteria such as E.coli and campylobacter and protozoa such as cryptosporidium and giardia are among the pathogens that have been found in water from these sources.
All can cause symptoms including diarrhoea, vomiting, stomach pains and fever.
Turner said this can be particularly dangerous for infants, elderly people and anyone with a suppressed immune system.
He said groundwater was usually of higher quality but could also become contaminated with bacteria and chemicals.
High levels of nitrate in groundwater can endanger babies who are fed infant formula. They can develop a serious condition that affects how oxygen is circulated around the body, Turner said.
Groundwater contamination can be caused by fertilisers and agricultural chemicals, animal waste in areas of intensive farming, on-site sewage disposal systems and industrial and food-processing waste.
"We would recommend that people using groundwater in an area of intensive farming or intensive fertiliser use should have their water tested.
"We would also recommend that drinking water collected in a tank undergoes some form of treatment before it is consumed,'' Turner said.
Treatment includes adding bleach to the water tank, filters and UV or simply boiling the water.
A new Water Services Bill that will comprehensively reform the drinking water regulatory system is before a select committee.
Submissions are being accepted until March 2.
The bill includes targeted reforms to improve the regulation and performance of wastewater and stormwater networks. It was instigated after 5000 people became sick and four died because of contaminated water in Havelock North in 2016.
As part of the overhaul, dedicated regulator Taumata Arowai has been set up and will start operating this year once a board and Māori advisory group has been appointed.
The new body is governed by the Water Services Regulator Act, which was passed in July last year.
Its objectives are to protect and promote safe drinking water and ensure drinking water suppliers are registered and have a safety plan.
Turner said the bill sets out the new regulatory framework and divides the current drinking water standards into two parts. The maximum acceptable values will become "standards" and the operational requirements will become "rules". These are based on standards set by the World Health Organisation.
Turner said Northlanders and bach owners relied heavily on water tanks, and summer visitors increased demand during the holiday season.
He said tanks should be regularly maintained by cleaning out the sediment, checking spouting and clearing any fallen leaves, twigs, dead birds or possums.
First-flush diverters can be installed to keep the first rain out of the tank if deposits have built up after a period of no rain.
"A lot of people head to Northland for holidays, which increases demand on water suppliers, especially during a drought.
"Water restrictions are put in place by councils to maintain supplies for towns but also to ensure there is sufficient water for water carriers to replenish rural tanks.
"The use of untreated water to refill tanks is not recommended due to the possible presence of pathogens in the water,'' Turner said.