To save you the job of reading the link I added upthread I have pasted it here and bolded the relevant references.
A plumber, Lorenzo Mansutti, was the only person called to give evidence on behalf of the nurse as the defence closed its case on Wednesday.
Letby, 33, denies murdering seven children and attempting to kill 10 others on the neo-natal unit at the Countess of Chester hospital in the year to June 2016.
Mansutti, who has worked as a plumber on the hospital estate since 1986, confirmed Letby's recollection of an incident she suggested may have contributed to the unexplained deaths of babies.
Giving evidence last month, Letby, 33, said parts of the neonatal unit were
"not a safe working environment" because there were "often plumbing issues".
She told jurors: "We used to have raw sewage coming out of the sinks [and] coming out on the floor in nursery one."
Letby said the issues could have played a role in the unexplained deaths and collapses of babies as staff were unable to clean their hands. "It's a contributory issue if the unit is dirty and staff were unable to wash their hands," she said.
Mansutti said there were issues with the drainage system at the hospital's women and children's building which he said was built in the late 1960s and opened in the 1970s.
Asked by Benjamin Myers KC, defending, how often he was called out for
"these sort of issues" in 2015 and 2016, the witness replied: “ for the whole building it was maybe weekly “
He said he recalled that "foul water" had come out of a sink in the intensive care suite - as Letby had claimed - but that he believed it was the only time this happened as improvement works were carried out afterwards.
Mansutti said he did not attend the incident himself and could not recall when it happened as there was no formal record of it on the hospital's Datix risk management system.
He gave details of 11 other plumbing incidents in the same building in the year to June 2016, the period when Letby allegedly murdered babies.
Under cross examination by the prosecutor, Nick Johnson KC, Mansutti accepted that about half of those issues happened in the labour suite and there would be “ no consequences “ on the neonatal unit.
So ….Air injected, internal bleeding, bleeding and trauma in the throat, synthetic insulin added to babies TPN bags, over feeding with milk causing quadriplegic cerebral palsy, injections of air and liver injury to reference some of Letbys preferred methods to kill the babies on the indictment and funnily enough NO babies died of conditions related to the hygiene on the NICU.