MOUNTLAKE TERRACE — The ability to text 911 has been live in Snohomish County for three weeks now.

The good news is people are making use of the service.

The bad news is that so far, 81 percent of the texts received haven’t been for emergencies.

Dispatchers are averaging two or three texts to 911 a day now in the county, as they expected, said Debbie Grady, executive director for SNOCOM, the dispatch center based in Mountlake Terrace. SNOCOM received 911 texts from 36 people as of Thursday.

Four of those reports were valid, and would not have been better served as voice calls, Grady said. Two were from deaf people and two were from domestic-violence victims — two populations the service was designed to help. The nonemergency texts included complaints about speeders and neighborhood noise, according to a SNOCOM memo.

The message remains, “Call if you can, text if you can’t.”

“We will ask people if they can safely talk and if they say yes they can then we immediately call them,” Grady said. “You should text only when a voice call is not possible.”

Texts from people only wanting to test the service have petered off since the first few days, but prank texts continue, Grady said.

Just this past week, someone said they were being robbed. When dispatchers began asking questions, the person “realized it was serious and their prank may have gone a little bit too far,” Grady said.

In such cases, police officers are still sent to make sure everything is OK. There’s been an assumption that 911 texts — including pranks — can be anonymous. That’s not true.

A text provides less accurate location information than a land line call. It takes more time to pinpoint someone, but it’s possible, Grady said.

No matter what, in an emergency, the text should include a location, Grady said. Messages also must be 140 characters or fewer. Some wireless providers will cut up long messages into pieces, which might not all reach 911. A short text allows dispatchers to establish a dialogue and ask needed questions.

“There will be lots of opportunity to include information, but if they make the text too long, we may not get the message,” Grady said.

Snohomish County was only the second county in the state to roll out the service.

So far, more than eight more counties in Washington either are testing the service or talking about it, said Laura Caster, a Snohomish County 911 manager. Seeing it launched here is “taking some of the unknowns away,” she said.

Dispatch centers hope to work with the various wireless carriers on the existing limitations for 911 texting.

Rikki King: 425-339-3449; rking@heraldnet.com.

911 texting

Location information might not be accurate when texting 911.

It’s not anonymous, so don’t prank. They have your phone number.

Texting is not available in all areas and not available while phone is roaming.

Translation for non-English speakers is not available.

The service requires a cellphone plan with texting capability.

The 911 center cannot control the delivery of the message from the carrier. Texting is a slower method for reporting emergencies than voice calls, except for those with specific speech and hearing disabilities. It also is meant to help people who cannot safely make a voice call, including hostage situations and domestic-violence victims.

Keep messages brief. Texts are limited to 140 characters.

Do not text and drive.