Paris Alston: This is GBH's Morning Edition. Today in the forecast we are expecting, you guessed it, more rain. And we've been saying that a whole lot lately.

Jeremy Siegel: For the latest on the weather, why it has been so wet, and what happens to all the salt that has been hanging out on the ground when it rains like this, we're joined by meteorologist Dave Epstein. Hey there, Dave.

Dave Epstein: Hello. How are you guys doing?

Alston: Doing well. So, Dave, we woke up yesterday to a dusting of snow. Of course, there was salt on the ground to help melt that. Now we're waking up to a wet morning and we have more rain in the forecast. So before we get to talking about the salt, how much rain could we see tonight?

Epstein: Yeah. We're not going to see a lot. I think it'll be a little bit less than last night, maybe generally a quarter to a half an inch, some places, maybe a little more than that. But the ground is certainly saturated, it will melt a little more of the snow. Up out Metro West, there's still an inch or two on the ground, and a lot of that's going to melt with temperatures fairly mild this morning. We're actually going to cool off during the afternoon. We'll be back down into the 40s as we head for the overnight hours. No danger of any frozen precipitation, but it's definitely the mildest hours are occurring right now.

Siegel: Dave, every day on my walk to and from the car on my way to the studio here at GBH, I've been walking on grounds that are just caked in salt, which obviously is there to prevent ice, to prevent people from slipping and buildups of snow when it's nasty outside. But now it's going to be 50 degrees. It's going to be rainy. It made me curious, do we over salt the roads when we have just an immense buildup of it and then rain coming down?

Epstein: Yeah. I mean, it's a it's a hard question for me to answer. I'm not the DPW of all these different towns and they probably don't want me to be. But some of the things some of the towns are using, calcium chloride, magnesium chloride, or just sodium chloride, which is basically rock salt. That's what we used, you know back in the '40s, '50s, '60s, '70s until these newer products came out, newer technologies that work at colder temperatures. So the actual just straight salt, the rock salt, works at a temperature down to a certain amount. And then you can use calcium chloride at lower temperatures. So they'll use some of those things and they'll also pre-treat the roads. Now you'll often see strips that look wet down the roadways before a storm. And that's to kind of put that stuff down before the snow so it's easier to get at.

Alston: So, Dave, there is an environmental risk that comes with the use of salt on the roads. Remind us what that is and what happens when the salt does, when it gets warmer and it rains and the salt begins to run off.

Epstein: Yeah. So, you know, sodium chloride, which is straight salt — and again, different towns are using different things — does get into the environment and it can harm plants and it can harm like the grass strip that's near your lawn, or it can also harm — there's certain plants that are more susceptible to salt damage. Some of the spray, actually, as a car goes by and we start to melt it, that some of that spray can get onto some of the evergreens and that can also do damage to the plants. But the alternative, of course, is that no one's going to be safe on the roadways. So it's just sort of a necessary evil to use around here in terms of those big bulk, trucks that are going by with all of that.

Alston: And there's also wildlife, it can end up eating it, right? Maybe not necessarily knowing what the hazard is there, either.

Epstein: Yeah, that I don't know. I don't know whether —

Alston: Was reading about it, that's why I asked you. On the EPA website.

Siegel: Something else, Dave, that we have been reading about is the alternatives that do exist for salt. You know, you said that can't be used for big bulk city treating of ground, but it's stuff that you can use at home. You and I have talked a little bit about this. You said you don't want to be the DPW for cities, but maybe you can be for our homes. I was looking at a list of the alternatives, and I'm curious your thoughts on the different ones, whether we could just go through the list and you could say if you think it works or doesn't, or if you don't know. Sand: does sand work?

Epstein: Yes. Sand's a great alternative in terms of traction. So if you have ice and you just want to put down sand. So I know the town of Natick allows you to get free sand and some of the towns just have it available and you can just put sand down. And if it's straight sand, there's no real environmental risk with that. It's just sand. It's going to wash away. You'll have to clean it up in the spring. But that's actually what I use, is I use a lot of sand. Sometimes I'll even use some other, like, a little bit of crushed gravel or something like that, if I just need a little bit of traction around the yard.

Siegel: Also on our list here is kitty litter, which I'm assuming is similar to sand. Paris, what else are we looking at?

Alston: We have vinegar, which was a surprising one to me because I didn't necessarily think about it as a melting agent. But the citric acid helps to melt snow and ice. Also, a big one that we were talking about earlier was sugar beet juice.

Siegel: Does that work, Dave?

Epstein: I've never used it. I do know that it's available, on some of the online places. It's a little more expensive. I have looked at it, you know, it's, in the $60 range for a pretty big bag of it. I don't know how long it would last. But, yeah, it's a sugar beet derivative is I think what I read about that.

Alston: We heard it smells, too. So that that could be a cost to using that.

Siegel: It might taste good, though.

Alston: Well, that is meteorologist Dave Epstein. Dave, there are a whole bunch of other ones. Things like alfalfa meal, coffee grinds. You mentioned calcium chloride. So certainly some things to maybe investigate for folks who want, you might want to use an alternative to rock salt on their sidewalks. Thank you so much. Always good to talk to you.

Epstein: You're welcome.

Siegel: You're listening to GBH News.

Meteorologist Dave Epstein is our go-to person for pressing weather questions on everything from winter blizzards to summer droughts. He’s also a horticulturist, meaning he’s an expert in anything that grows leaves and flowers. GBH's Morning Edition asked our audience for weather and gardening questions, and Epstein graciously answered them on the air. This transcript has been edited for clarity.

Have a gardening or weather question for meteorologist Dave Epstein? Tweet him  @GrowingWisdom, email us at  thewakeup@wgbh.org, or text 617-300-2008.

“Every day on my walk to and from the car on my way to the studio here at GBH, I've been walking on grounds that are just caked in salt, which obviously is there to prevent ice, to prevent people from slipping and buildups of snow when it's nasty outside. But now it's going to be 50 degrees. It's going to be rainy. It made me curious: Do we over salt the roads when we have just an immense buildup of it and then rain coming down?” —Jeremy Siegel, co-host, GBH’s Morning Edition

There are many things cities and towns use to prevent icy roads, Epstein said. He emphasized that he is not a member of any municipality’s Department of Public Works, nor the state’s Department of Environmental Protection.

“But some of the things some of the towns are using: Calcium chloride, magnesium chloride, or just sodium chloride, which is basically rock salt,” Epstein said. “The actual just straight salt, the rock salt, works at a temperature down to a certain amount. And then you can use calcium chloride at lower temperatures.”

When snow melts or rain comes and the salt washes off the roads, in often ends up in nearby soil, he said.

“It can harm plants and it can harm the grass strip that's near your lawn,” he said. “As a car goes by and we start to melt it, that some of that spray can get onto some of the evergreens and that can also do damage to the plants.”

There are some alternatives people can use around their homes, Epstein said, though he noted that they may not be effective, affordable, or feasible enough to use on a city- or town-wide scale.

“Sand's a great alternative in terms of traction,” he said. “I know the town of Natick allows you to get free sand and some of the towns just have it available and you can just put sand down. And if it's straight sand, there's no real environmental risk with that. It's just sand. It's going to wash away. You'll have to clean it up in the spring. But that's actually what I use, is I use a lot of sand.”

He's also looked into using products made with sugar beet juice for use around his home.

“It's a little more expensive,” Epstein said. “It's in the $60 range for a pretty big bag of it. I don't know how long it would last.”

For the time being, Epstein said, he understands why cities and towns use a heavy hand when they salt the roads.

“The alternative, of course, is that no one's going to be safe on the roadways,” he said. “It's just sort of a necessary evil to use around here in terms of those big bulk, trucks that are going by with all of that.”