Lake water supply system
Looking into doing a lake water supply system at my cabin. It's on an island but has power so I can use a submersible pump and internal heat trace line. The cabin sits 20' above water line and about 70' back from the shoreline. My pressure tank is at the back of the cabin so I'll have a run of about 120 feet of water line. I'm planning to use 1" blue potable water Pex line. I'm considering setting it up as a drain back system that can be shut in in the summer to operate normally without the drain back in use. In that case I'd only be running internal heat trace through a short section passing through the ice at the shoreline. Alternatively I could run an internal heat trace the entire length and install a bleed valve at the shoreline I could open and drain the system when I leave for extended periods. That would leave only the short section passing through the ice to freeze which I could thaw with the internal heat trace when I returned. Has anyone setup a similar system and have any advise? Or know a contractor with experience in setting up these kinds of systems?
In Minnesota, Gunflint trail area, we installed lake systems on every cabin we constructed.
In the lake we put a 5/8" rebar, welded tripod down that had cross braces about one foot off the bottom of the legs. These braces allowed the legs to settle into the bottom but not sink. The bottom the tripod was weighted down too.
The pump was suspended off the top junction of the three legs so it would remain six feet off the bottom and out of any turbulence/dirty water caused by wind and waves.
1-1/2" black water line was run between the pump and pressure tank-a continuous piece...no splices. Get the higher pressure rated line for better freezing protection.
Where the water line runs to shallow water, near shore, we would slip 4" drain line (flexible) over the water line for protection from abrasion by wave action. The line was buried wherever possible.
The heat line was called 'Cal-rod' out of Canada (sorry no link). This would run from the just before the pressure tank (into a special fitting) to below ice levels in the lake. We would push this (or pull with a string) in ourselves.
At the end of the summer season the water line was allowed to freeze. If a cabin owner came up they could turn the 'cal-rod' on, let it thaw the water line for 1/2 a day then turn the water system on.
You need to take care that none of the fittings are susceptible to freezing.
Our systems were hard plumbed and sloped (copper) with two drain points-one for the cold side and one for the hot side.
I could open the two drain points and water heater, put antifreeze in the drains, dry out the toilets and leave for the day, returning the next morning to check that all had drained completely and then turn the heat off.