Environment Agency Wales are continuing to investigate the Bryn Compost site in Gelligaer after nearby residents complained of a stench coming from it.
Earlier this month residents of Gelligaer, Nelson and Penybryn delivered a petition to the Welsh Assembly demanding the composting site be shut down because of the stench.
The Environment Agency, in its initial investigation, has identified key changes to the way the site works which should improve the situation for local people.
Officers from Environment Agency Wales though have said they will intensify their investigation and will install a specialist air quality monitoring unit nearby.
Graham Hillier, area manager, Environment Agency Wales, said: “As the situation has deteriorated we are now stepping up our regulatory work at the site. A lot of work has been carried out by the operators at our insistence, but we are not satisfied with the results.
“We have sent our national odour expert to the site and he has drawn up a list of actions that will make a difference. We will make sure these actions will be followed. The new monitoring unit there will also give us a more detailed picture of the problems there.
“We have contributed considerable time and resource into investigating the problems at the site and this will continue. We have also reviewed their environmental permit and will consider taking the relevant action as we work to improve the situation for local people.”