An employer has been sent to prison for six months after an employee was killed when a trench collapsed on him.

Swansea Magistrates’ Court heard how William Ryan Evans was contracted to construct a drainage field comprising of infiltration pipes laid at the bottom of trenches. He employed two workers and a subcontractor excavator to undertake the work at Longstone Farm, in Pembrokeshire.

Hywel Glyndwr Richards, aged 54, entered the trench to remove a clump of soil that had fallen into the trench. The trench walls collapsed, burying him. He died at the scene.

An investigation by the Health & Safety Executive (HSE) into the incident which occurred on 26 June 2012 found that the work was not planned appropriately and the risk assessment was not suitable or sufficient. The workers were not appropriately trained and suitable equipment to prevent a collapse was not provided.

At Swansea Crown Court on Monday 11 April, William Ryan Evans, of Blaenwaun Twr, Trelech, Carmarthenshire, was found guilty of breaching Section 2 of the Health & Safety at Work etc Act 1974 and was given a six month custodial sentence.

HSE Inspector Phil Nicolle said: “This tragic incident could have been prevented by undertaking a suitable and sufficient assessment of the risks, providing the correct equipment for safe working methods to the workers and managing and monitoring the work to ensure it was done safely.

“Work in excavations needs to be properly planned, managed and monitored to ensure no one enters an excavation deeper than 1.2m without adequate controls in place to prevent a collapse.”

Hywel Richards’ family said: “Dad was... the glue that kept us all together. Our family was devastated by his sudden death. We have wondered so many times why this has happened to us. We were meant to grow up with Dad as our guide; the man we looked up to and loved so much.

“Family gatherings and celebrations, once joyous occasions, are now ruined because dad is not there. Today, and for the rest of our lives, we are mourning the loss of dad, our best friend, our confidant and protector. Quite simply, he has left a space that will never be filled. We hope that lessons will be learned from dad’s death.”

For further information on safety in excavations visit:http://www.hse.gov.uk/construction/safetytopics/excavations.htm