Plans are being developed to increase sewage wastewater testing to identify coronavirus spikes in Northern Ireland.
Scientists established last year that the virus's genetic material could be identified in human waste.
Testing is currently being carried out on samples from wastewater sites at Ballynacor (Craigavon) and Dunmurry.
That will be scaled up to help develop a Covid-19 early warning system under Department of Agriculture, Environment and Rural Affairs (Daera) plans.
Under the plans, a number of additional sites will be added between April and June, with further sites covering all of NI's population added in the second half of 2021.
It is hoped the expansion will allow for the long-term development of a wastewater surveillance programme that can quickly detect local Covid-19 outbreaks and help identify new variants of the virus.
Agriculture and Environment Minister Gordon Lyons said testing to date has "already yielded successful results and will now be scaled up with further sites being monitored in the coming months".
Testing also allows for virus detection even when there are only asymptomatic Covid-19 cases in the community.
Daera has committed £400,000 to the project - a collaboration between Queens University Belfast, the Regional Virology Laboratory and the Public Health Agency (PHA).
Minister Lyons added: "We need to use every possible weapon we have to fight Covid-19, quickly identify where outbreaks are occurring and stop the spread.
"Wastewater sampling can help us keep a watchful eye on levels of the SARS-Cov-2 virus in the community and allow health teams to take early actions".
The PHA and Stormont's Department of Health said wastewater surveillance will form an important part of the virus' management long term.
Health Minister Robin Swann said it will "become an important element of continuing arrangements to monitor and track virus activity".
He added: "Importantly, wastewater surveillance can help detect the SARS-Cov-2 virus in both symptomatic and asymptomatic populations and as such will have an important role in helping to monitor overall viral activity and to identify any new variants that may emerge".
Sewage testing could also be used in the long term to identify a number of other pathogens including norovirus, and both hepatitis A and E.