I live in lakes and often use the springs to drink from, as mentioned above I would not recommend drinking from pools, lakes and especially tarns. I always do a quick visual assessment and I always try to drink from where the spring exits the rock face.
You just need to have common sense but to be honest a filter system is best practice always.
Scafell is causing a few issues this year. Lords rake has some very loose and large debris, Foxes tarn also has a few issues, as I understand, and as for Broad stand; well, my wife and myself were having lunch on Mickledore ridge last Saturday and sadly a chap sliped from, said, Broadstand (60Metres) and was critically injured. Several of us worked to keep him alive until the MRT and paramedics arrived and he was air lifted to hospital and has subsequently been moved to a more specialised unit. He has severe multiple injuries and is very lucky to be alive; and he expected to make a full recovery but this will be an exceedingly long haul for him.
Being a strong and a very experienced fell runner may have been the only thing that kept him alive.
All who intend on going onto Scafell (not to be confused with the Pike) Please, Please, be careful.
Our thoughts are with the family concerned and a very, very, special thank you to Wasdale Mountain rescue team, the paramedics and Karen the flying doctor.
We use Innov-8 Rocklite 390GTX fabric boots in really bad weather and in snow (Innov-8 Rocklite 320 shoes in good to fair weather). The boots are very comfy, good weight compromise and will take any gaiter and in winter; will take Kahtoola crapons or microspikes; not for major ice climbing but sufficient for fell tops in snow and ice walking/packing.
We make our own thermal insoles out of Loft insulating foil covered bubble wrap, this only lasts a couple of trips as your weight crushes the bubbles, but works well for a day trip or old closed cell sleeping mat...works a treat.
As with all water proof membranes, its ok to keep water out but if water does get in, it stays in and is hard to dry out, if you are on multi-day trips, but we have had very little trouble with this combination in the last 4 years.