Dear Umbra, I've been turning in my used alkaline batteries at the local drug store's photo department, mine being Savon here in Southern California. It appears they recycle their spent film cans and cartridges, as well as cameras and batteries. At least this is what I have surmised when I have dropped off my used batteries and the attendants have not refused me. It wouldn't hurt for others to do the same. Besides, once when asking a local recycler what they accepted, the response was, "If we get enough of anything, we'll do our damnedest to find a user!" JanetSherman …

Dear Umbra, While you were warning folks to plan ahead for a potential water-tank failure, I thought you should mention the natural gas heat-on-demand systems that they should use to replace their tanks. Last spring, when our 50-gallon tank decided to give our basement floor a thorough cleaning, we had to scramble to find an energy-efficient alternative. First, we had trouble finding a plumber who knew how to install the new energy-friendly heat-on-demand systems. Then, we ended up paying a premium price because it seems these systems are all the rage in new McMansion construction. The suppliers were having a …

Dear Umbra, When you suggested that someone may want wood heat because it "makes you feel like a country stud," you made an erroneous assumption -- that your audience is entirely urban. Here in Skamokawa, Wash., many a mile from the nearest natural gas line, the choices are essentially wood or electricity. In September, my family installed a Blaze King wood stove, which uses a catalytic converter to convert smoke to heat. Not only does the wood burn so completely that we have not yet had to clean out any ash, but when the stove is up to temperature, there …

Dear Umbra, I am a completely eco-friendly person and strive to have my family follow in those footsteps. We have a recycling system -- one my canned-beer-drinking dad refuses to abide by. (Not that I'm criticizing canned beer or my father. Both are good.) He refuses to recycle his cans, and I'm a little tired of digging them out of the garbage. Is there anything I could do to change his outlook on his wastefulness? RebeccaMt. Juliet, Tenn. Dearest Rebecca, Have you tried the Reasonable Conversation? It's a good turnabout tactic in certain parent-child relationships. If your dad has sat …

Dear Umbra, I am a huge fan of Guinness, often referring to it as Nectar of the Gods. Question is, are the cans with the cool nitrous plastic doohickeys in them recyclable? I've got a bet riding on this with the significant other. Thanks for enlightenment. MelissaDenver, Colo. Dearest Melissa, Yes. Guinness recycling is good for you. That little ball is known as a widget, which is another word for doohickey. It's made of polypropylene, has a small hole, and, during the canning process, gets filled with nitrogen gas and a teeny-tiny bit of Guinness itself. The pressure in the …

Dear Umbra, My friends and I consume a fair amount of beer, and we're wondering: What's worse for the environment, buying beer in cans or in bottles? KellyManitoba, Canada Dearest Kelly, Thank you for giving me a reason to look up the Earth's mineral-reserves map in my atlas. I've learned fascinating things about aluminum and glass and discussed the whole matter with lifecycle analysis experts and recycling folks (including my pal Peke the recycling expert, who just biked over in freezing weather; let us all be inspired by Peke). The clear answer is: Drink locally bottled beer in glass bottles …

Dear Umbra, I have a question that's been nagging at me for some time. Since I have a water heater inside my house, any waste heat from the water heater contributes to heating the house. Does it still make sense in terms of energy savings to put an insulating blanket on the water heater? KurtLittleton, Colo. Dearest Kurt, Getting tanked.Photo: PNNL. After space heat -- that is, heating your entire home -- water heaters are the largest household energy consumers. Part of the reason the bill and the environmental burden are so high is that a tank water heater keeps …

Dear Umbra, My housemates and I are engaged in an ongoing argument about the heat (gas) in our somewhat old house. I argue that for the minimum eight hours that we are out of the house during the day, we should turn our heat down to at least 62 degrees. They argue that we should leave it at 68 at all times, because it takes more energy to heat up the house later when we all arrive home. Not surprisingly, we can't agree about a sleeping temperature at night, either. Can you settle this "heated" debate? Will B. ColdWashington, D.C. …

Dear Umbra, Can you shed some light (or some warmth) on the most environmentally sound ways to heat one's home this winter? Natural gas over coal and oil for its lower carbon (and particulate) content? What about fireplaces: good or bad? Would burning gas logs be a good alternative to burning real wood? Thanks for your help! JanetWashington, D.C. Dearest Janet, What we cold eco-folks are looking for is a heat source that is clean to produce, clean to burn, energy-efficient, affordable, and renewable. Look back at your choices with that in mind, and you'll see that natural gas, although …

Dear Umbra, Does one really need to wash produce off the shelf or out of the bag? I've been eating vegetables as they are for years. Does it really do any good to wash them? If they are contaminated internally, then washing the outside won't help, will it? JaneSteubenville, Ohio Dearest Jane, Please wash your veggies. Internal contamination from pesticides, herbicides, waxes, and the wages of sin won't be washed away, but some life-threatening external contamination will. You'll want to wash these greens. Trust us.Photo: USDA Think about your produce. It may have traveled from Mexico, China, California, or Chile. …