Sue Arnold: They are funny things, septic tanks

The real problem with our medieval drainage system, as every sewage anorak will tell you, is modern living

At half past seven last Wednesday morning, two young men and a bulldozer turned up at our cottage in Killinghurst to install a new septic tank. Ten cups of tea and 12 hours later, they left, having bulldozed, dug, smashed, scraped, infilled, levelled and landscaped, leaving me wondering vaguely why my two older sons went off to university to study Spanish and ancient history when they would clearly have been much happier working out of doors with big boys' toys. And, what's more, getting paid a great deal more, I dare say, than your average Spanish teacher or assistant curator at the British Museum.

Big city building sites always used to have public viewing platforms. I don't suppose they are allowed to any more due to new EU health and safety regulations. But back in the old days, at lunchtime, these viewing areas would be packed with overweight pasty-looking men in suits watching lean, wiry builders with six packs hoisting pallets, grappling girders and operating cranes and bulldozers with the dexterity of flautists.

Watching the long, yellow arm of a bulldozer rhythmically scooping soil into a pile has a trancelike effect on the viewer, I discovered. If I stared at it much longer, I'd probably regress to some traumatic period in my childhood and start shouting for my Indian ayah.

Had they not been working so hard, I would have welcomed the opportunity to chat to my septic tank installers about the viability of reprocessing domestic waste in the same way that the green inhabitants of an eco-friendly block of flats in Sweden are apparently reprocessing theirs.

It works, as far as I remember, in much the same way as power stations fuelled by methane gas from animal dung and chicken manure. In the basement of this ground-breaking Swedish housing project, there was this amazing sewage treatment unit, doubtless designed by Ikea, that transformed the solids into fuel, the liquid into Perrier - still and sparkling - and the residents into happy campers. It surely couldn't be beyond the bounds of commercial viability to produce smaller versions for individual households.

In Killinghurst and its environs, everyone has septic tanks because there's no mains drainage, even on the major roads. The council has been threatening to put it in for years, but, since it will cost upwards of £30m, they are concentrating on cutting the verges instead.

They're funny things, septic tanks. Some are invisible; others, like our old one, advertise their presence only too aggressively, particularly when the wind blows from the north. Or, come to think of it, the east, west or south. I'm sure it leaked. The new ones are made of fibreglass and look like enormous garlic bulbs, unlike the old models, which were brick-built.

But the real problem with this medieval drainage system, as every sewage anorak will tell you (and believe me, Killinghurst is full of people who will corner you in the post office and bang on for hours about their new treatment plants), is modern living. We wash too much. Bathrooms en suite, washing machines, dishwashers - Mr and Mrs William Wordsworth in Dove Cottage were lucky to have one bath a week with shared bathwater. "Detergents, what's a detergent?" I can hear Dorothy saying. "I wash William's socks in the stream."

At least in the country we have some control over our waste disposal. In London the sewage system, which is Victorian, is by all accounts on its last legs, so little has been spent on its repair and there's absolutely nothing we can do about it. A couple of weeks ago when the capital was roasting in temperatures approaching 90F, there was the most appalling whiff outside our flat, not just in the King's Road, which is always pretty smelly, but in the little streets leading down to the river. I thought there must be roadworks somewhere.

Whenever the gas, electricity, telephone or cable TV men are digging up the Tarmac, a fetid stench pervades the entire thoroughfare from Sloane Square to World's End, making eating alfresco in Chelsea rather less romantic than it sounds. But no, for once there wasn't a roadwork sign in sight. "It's the drains," said the supermarket manager. "It's because we haven't had any rain for so long. Heaven knows what it'll be like in August."

Heaven knows, but fortunately I won't. I'll be in Scotland thanking my lucky stars that as usual it's raining stair-rods. It's what you call swings and roundabouts.