Are they connected to the sewer system? Or do they discharge their effluence into the lake?

> Or do they discharge their effluence into the lake?

Given this is the Netherlands and this appears to be a wealthy area, I'm quite sure they don't. Guessing they either have septic tanks or holding tanks that need to be pumped regularly.

	▲	ProllyInfamous 20 hours ago \| parent [-]
		I have a degree which allows me to work in few fields, but wastewater management is one of those fields (which I have worked in, front-line (directly) >gross<): no water is "clean" — it's varying shades of "acceptable" ---- There is a running joke (hundred+ years now) that the famous "Ruby Falls" on Lookout Mountain is in fact better named "Poopy Falls" – since the primary water source are the few hundred septic drainlines higher-up the mountain's-top. <https://en.wikipedia.org/wiki/Ruby_Falls> ---- If you have any open cuts/sores, do NOT swim in any outdoor water.