The chartered accountant, who observes he is the first Scot to be chief executive of Scottish Water, talks with some relish over sandwiches in the Blythswood Square hotel in Glasgow about what his team is doing to tackle and prevent problems in the sewerage system.
He also highlights the pride which customers of Scottish Water have in the quality of the country's drinking water.
And he talks with a passion about the beneficial impact of his organisation's investment programme, which amounts to about £470 million to £480m per annum, on the Scottish construction sector, the wider economy north of the Border, and on employment. Scottish Water itself employs about 3400 people, as well as providing large amounts of work for sub-contractors.
At a time of high youth unemployment, Mr Millican highlights Scottish Water's apprenticeship programmes, as well as its graduate recruitment programme. He also underlines efforts by Scottish Water to work with its partners in its supply chain to ensure they take on apprentices.
Mr Millican comes across as passionate about the needs of customers and also about the state ownership of Scottish Water. He believes that the interests of his organisation's owner, the Scottish Government, are aligned with those of customers under this model.
And he talks enthusiastically about Scottish Water's vision of becoming the country's most valued and trusted business.
The 49-year-old is a veteran of the water industry north of the Border.
Mr Millican joined East of Scotland Water in 1996, when it started up. He was part of the initial leadership team at Scottish Water when it was formed in 2002 through the combination of the West of Scotland, East of Scotland, and North of Scotland water authorities, and filled the role of finance and regulation director for more than a decade.
He became interim chief executive of Scottish Water last autumn, following the untimely death from cancer of Richard Ackroyd, who was 53 and had led the organisation for more than four years.
Mr Millican, who became chief executive on a permanent basis from February 1, recalls that one of the twice-yearly programmes of gatherings around the country of about 500 of Scottish Water's senior staff took place last November, shortly after Mr Ackroyd's death in late October.
He says: "We were able to remember Richard and recognise him as a person - what he brought - and also to give everyone a chance to grieve, but also, as a leadership team, give everyone a chance to commit to our forward direction."
Mr Millican notes he had been interim chief executive of Scottish Water previously, between the departure in November 2007 of Jon Hargreaves, who took early retirement, and the arrival of Mr Ackroyd in March 2008.
Referring to his appointment as interim chief executive last autumn, Mr Millican says: "Obviously, it was quite a sudden situation. In a sense, it wasn't strange for me to step into the role because I had done it before, although we were in a very different place."
He adds: "I was surprised by how relatively straightforward it was, and I think there are a number of reasons for that."
Listing these reasons, he adds: "I think, because of the business generally performing so well, I think because of the support I have got from the rest of the executive team and the broader management team, and I guess because I have been in the business for such a long time."
Although from a finance background, Mr Millican is steeped in the nitty-gritty of the water and sewerage business.
For instance, he highlights education programmes by Scottish Water to stop people flushing things down the toilet which are likely to block the sewers.
And he talks with some fascination about a "fatberg" in the sewers under the London suburb of Kingston upon Thames which was about the size of a double-decker bus.
Mr Millican says: "The two problems can be people who put hot oil into a sewer. It gets cold and congeals. The other problem is you can get things like nappies and wet wipes put down.
"They can accumulate. If it creates a big enough blockage, it means the sewage can't get through and it can then back up on to an open space, on to a road, or a garden, or a public area, or whatever."
Blockages in sewers are handled by what Scottish Water refers to as its "choke team".
Mr Millican, while he makes it his business to tour Scottish Water sites around the country, including water treatment works, pumping stations, sludge treatment facilities, and reservoirs, does not venture down the sewers. He cites health and safety considerations in this regard.
Asked if he has had to go down the sewers, he replies: "I have been to many places. Probably, from a health and safety perspective, there would be an issue of me going into a confined space without adequate training."
However, while acutely aware of the daily operational issues for Scottish Water staff and enthusiastic about the part which social media such as Twitter can play in keeping customers updated swiftly on efforts to resolve any problems, Mr Millican also hammers home the importance of taking a very long-term view when making investment decisions.
In particular, he highlights recent work on forming strategic priorities for the next 25 years, in consultation with customers and with the Scottish Government in its role as owner.
Among customers' priorities is further investment to help prevent rainfall causing flooding from sewers.
In February, Scottish Water unveiled a £250m, five-year programme of investment in the waste-water network of Greater Glasgow. This includes measures to transport surface water away from known "pinch points", thus reducing the risk of flooding.
Asked whether the chief executive role has proved much as he had expected, Mr Millican replies: "It has probably been much better than I expected. Bear in mind I didn't apply for this job. I was literally phoned up and (asked), 'Would you take it up?', initially on an interim basis."
Noting that this conversation with the board had moved on quickly to the subject of him taking up the role on a permanent basis, he adds: "I went from a position of never having envisaged doing this to going on to a position of saying, 'I am happy to do it'.
"I view it as a real privilege. I think it is a fantastic business, fantastic product. I am absolutely delighted to be steering it to the next stage of the journey, to make it better for our great country."
Presumably with an eye on the constitutional debate, he emphasises: "By the way, that is not a political point."
Asked about the advantages and disadvantages of Scottish Water being in state ownership, Mr Millican identifies only pluses.
He says: "I think the ownership system we have in Scotland works really well for us. There is a real strategic alignment between what matters to our owner, government, and what matters to our customers, which is about getting really high-quality customer service, really high-quality water, at an affordable price for customers. We get access to really cost-effective borrowing. We can access debt at effectively government borrowing rates. That feeds through to lower charges for our customers."
Mr Millican takes pride in the fact the average annual water and sewerage charge for households served by Scottish Water is more than £50 below that for residential customers of the privatised companies in England and Wales.
Noting his travels as chief executive have taken him to Stranraer, Shetland, and Cumnock recently, he says: "I have lived in Scotland for all but three years of my life and I have seen parts of the country I have never seen in my life."
Mr Millican worked for accountancy firm Price Waterhouse in Scotland between 1986 and 1990. He worked for the firm in New Zealand, based in Wellington, in 1990 and 1991. He worked for Tyco in Australia from 1991 to 1993, a job which gave him the opportunity to travel around the vast country.
Observing the Blythswood Square hotel has served tap water with his coffee and sandwiches, Mr Millican says: "To me that just shows, if a five-star hotel like this is voluntarily providing tap water, it shows how happy they are to be associated with that, as being a really high-quality product. Five years ago, that just didn't happen. It is the fact you get so many good places now that are just providing it as a matter of course because they know it is a great product."
Unable to resist a dig at the privatised water companies south of the Border, he adds: "You sometimes have to ask for it (tap water) more in England, I have noticed. I wonder why."