This might, Manedalli concedes, be because he is wearing his uniform, or because we are staring at the bin. I'm disappointed, but Manedalli isn't: "My job is to minimise offences," he says. "So if they don't happen because people can see me standing here, I'm doing my job."

Until last week, I had no idea there was such a thing as a street enforcement officer, whose job is to deal with problems such as flytipping, aggressive begging and antisocial behaviour. Then the news broke that Burcu Yesilyurt, who lives in Kew, southwest London, had been issued a fine outside Richmond station for pouring the remnants of a cup of coffee down a drain. She'd decided it would be safer than carrying the partially filled (reusable) cup on to the bus and potentially spilling it.

She was confronted by three officers who gave her the £150 fine, citing Section 33 of the Environmental Protection Act 1990, which makes it an offence to deposit or dispose of waste in a way likely to pollute land or water.

As the outcry against the fine grew, however, the council cancelled it, acknowledging that Yesilyurt would probably have been successful in appealing the fine.

Manedalli looks bemused when I bring up the Yesilyurt affair; perhaps even a little hurt that members of his profession have been brought into disrepute. "It's silly," he says. "It's OK to pour coffee down the drain. It's just coffee and water, it's not chemicals or oil or anything bad."

I point out that there must be a line somewhere, even with something as innocuous as coffee. If, say, someone drove up in a petrol tanker full of coffee, and began emptying it down the drain, would he let them off? He looks a little troubled. "If it was a business pouring that amount of coffee away, I'd be asking questions," he concedes.

Hashi Mohamed, a planning and environment barrister at Landmark Chambers, tells me that the fine should "never have been issued" by Richmond council's employees. "Ultimately, a cup of coffee going down the drains is much less likely to contaminate our watercourses than water companies, which are polluting our watercourses with sewage," he points out.

Some worry that cash-strapped councils are increasingly turning to fixed penalty fines to fund their services. K&C alone has 23 street enforcement officers: as Manedalli points out, if the team didn't make economic sense, it wouldn't exist.

As we patrol the swanky streets around Earls Court -- Manedalli takes 11,000 steps a day while on duty -- there are annoyingly few examples of the problems he typically tackles -- but then we notice a plywood board, leaning louchely against a wall, and Manedalli kicks into gear. He pulls on a pair of plastic gloves and checks the board for a name or address that might offer clues as to who left it there illegally. There are none. Undeterred, he gets out a big sticker, peels it off its pad with relish, and sticks it on the board. From there, it will be picked up by a member of the refuse collection team.

E-bikes are a growing part of Manedalli's work, he tells me as we move on: when he sees a Lime bike parked in the middle of a pavement, for instance, he alerts the company, which then has two hours to take action. The biggest fine Manedalli can issue is £1,000 for fly-tipping, which drops to £500 if paid within 14 days; the smallest is for idling car engines, £20.

Data on how much money councils make from fines issued for environmental offences is hard to come by. But it's clearly a significant operation at K&C, whose team has responded to more than 16,000 requests for assistance this year with problems such as abandoned vehicles and bikes, and fly-tipped mattresses and sofas. It's also issued more than 1,300 fines for littering, many of them on the spot.

Manedalli says he doesn't get a cut from any fines he hands out. And in general, he says, fines are a last resort -- those who haven't offended before are simply "educated" about where the law stands.

What do people say when he catches them? "Sometimes they'll say 'You don't have anything else to do with your life,'" he says, looking rather sad. "Or they might swear."

He wears a stab vest and a body camera, but has never been attacked: the key, he says, is to be "gentle and respectful", as people respond in kind. And in spite of the resentment of the people he confronts, "I love my job," he says. "I get to deal with different people every day. And I get to do investigative work, too, like when there's an address on something that's been fly-tipped. It's not a murder case, I know, but it's still interesting."