By Tracy Record

West Seattle Blog editor

Some call it “the hum”; some call it words we don’t publish here. It’s a mystery sound, most often reported at night, most often heard from eastern West Seattle. Whatever it is, e-mails and a variety of other messages, plus a spirited WSB Forum discussion, indicate the sound is back.

We first mentioned it here in the news section in 2009. It has come up now and then in the ensuing years. If you have never heard it – Julie in Highland Park resident recorded it early Monday and sent us the audio file. We uploaded it – the first :28 of this clip is fairly normal neighborhood noise, and then it begins.

She explains:

I made the attached recording on Sept 3 just after midnight (12:44 am) using the Voice Memo app on my iPhone, while I was standing on my front porch. I left the sound of a car driving by for context – the noise becomes louder and more audible at about 27 seconds into the recording. I just think that the fact that it registers at all on my cell phone shows how loud it is! This sound, which I can hear inside my house too, has been going on seemingly 24-7 since at least last Thursday.

The city investigates noise complaints. Ahead, what a city rep says about this, plus our conversation with a top manager at the industrial site some think might be to blame:

We inquired with the city Department of Planning and Development‘s noise inspector; the reply came from a department spokesperson, Bryan Stevens. His reply boils down to the same thing we’ve heard in the past – you have to tell them who’s to blame, before they’ll take it further:

As of yesterday, DPD had received one complaint about this specific concern in West Seattle. We are complaint-based, so we rely on the public to notify us of their specific issue and the location of the source. It can be difficult to pinpoint a noise source, especially when you have changes in topography in the immediate area. However, we need to know the potential source location in order to respond with an inspection. It often helps to know what time of day the noise is heard as well. We’re not aware of this complaint being filed in the recent past. In order to follow up, someone has to capture the noise to determine if a violation occurred (inspector or neighbor). The noise has to be louder than 45-50 dBA at the receiving site in order to be a violation. It was suggested by the complainant that the noise may be coming from Lafarge, but that is over 11,000 feet from the receiving site and has two hills between them and the site. We’d expect to have heard from neighbors immediately adjacent to Lafarge if that was the source, as they would have to be generate noise in the range of 150 dBA to travel 11,000 feet and still be a violation. The noise ordinance that DPD enforces is an objective standard, so hearing an unusual noise doesn’t always mean it’s a noise violation. Neighbors can report a potential violation by calling our noise abatement coordinators at (206) 684-7843 or (206) 615-1760. On this particular complaint, we would need neighbors to locate the source before we inspect.

So what about the contention by one WSB Forum member that it can be traced to the Lafarge plant in the 5400 block of West Marginal Way SW, on the western shore of the Duwamish River?

We talked early this morning with operations manager Jonathan Hall. He says our e-mail to the company yesterday asking for comment was the first he had heard of the noise. He’s been at the West Seattle plant for two years and while he says “people who have history here (mentioned) complaints over the years, there haven’t been any issues in the two years that I have been here.”

First, what this plant does: Hall reminded us that “about 70 percent of the plant (is) mothballed” – there was a significant operations cutback in 2010, with layoffs. They bring in cement from Richmond, B.C., via truck and rail, plus “a bit on barge.” Some slag-grinding is done to make a recycled cementitious product called NewCem. But Hall says the main stack, kiln, and cooler aren’t running; there was a tire-burning project that shut down before he even started. No coal or coke is being burned, and none of the previously problematic emissions.

But, Hall said, “There’s no way I can say it’s not us .. We’re always doing maintenance, and it’s certainly possible that a maintenance activity changed the way something sounds.”

The plant was operating over Labor Day weekend, he confirmed. Its schedule “depends on the season and needs.”

While he hadn’t heard from the city when we talked with him – and as our city response indicates, they aren’t to the stage of investigating anyone or anything without additional complaints – “if we can nail it down as coming from here,” Hall told WSB, “we’re keen to be able to work with people, to make reasonable improvements to make it go away, if in fact it is us.”

In hopes of finding out more, Lafarge has set up a voice mailbox so you can call with information if you hear it and you believe it’s coming from their plant. The number is 206-336-0988. If you call, the company says, you’ll get a call back, and they will check daily.

But first, as mentioned earlier, the city says they need to hear more about this before they can investigate, and they need specifics. Their inspectors are at (206) 684-7843 or (206) 615-1760.

2:52 PM UPDATE: DPD’s Bryan Stevens just sent a quick update: