Mourners may have to hold loved ones’ funerals in Weeley, Braintree or Chelmsford while eco-friendly equipment is installed at Colchester Crematorium.
The Mersea Road crematorium is to have two new cremators installed costing £750,000, with work starting on Wednesday and finishing in March.
The new cremators will enable Colchester Council to contribute to reducing mercury emissions.
They will include mercury abatement equipment, which will filter out mercury emissions and restrict the release of this into the environment.
Throughout the six-month installation period, the number of chapel services will be halved.
Penny Stynes, the crematorium and cemetery manager for Colchester Council, said: “During the installation period, one cremator will be in use whilst the other is installed.
“This will mean a reduction in the number of chapel services offered each day from a maximum of nine to a maximum of five.”
She added: “Colchester Crematorium will make every effort to accommodate those who require our services and we will be working closely with funeral directors to achieve this.
“In cases where we are unable to meet the needs of customers, funeral directors will be happy to contact neighbouring crematoria at Weeley, Chelmsford and Braintree to provide a satisfactory solution.”
After the six months, the number of cremations will return to about nine a day again.
Martin Hunt, the council’s portfolio holder for street and waste services, asked people to bear with them.
“Colchester Crematorium will ensure the dignity, care and professionalism of our services will remain during the installation period and services will be conducted sensitively with no disruption.”
Legislation requires crematoria to reduce their mercury emissions by 50 per cent by 2012, with the aim of completely eradicating this by 2020.