The din of pressure washers announced that people were hard at work as I approached a private dock on Chuckatuck Creek on Friday.

About the same time the volunteers participating in the United Way’s Day of Caring came into view, a gentle mist washed over me.

A faintly briny mist — a bit like oysters.

And there was a perfectly good reason for that. Four Suffolk Police officers and civilian employees, plus other volunteers, were helping the Nansemond River Preservation Alliance prepare for its latest round of oyster education.

Every year, NRPA uses “oyster growing” as a way to teach Suffolk public school students about the environment around them and how they can protect it.

Oyster floats are filled with infant oysters, which are deposited in waterways so the bivalves can feed and grow. (Later, they become part of oyster reefs, filtering pollutants from the water.)

During this time, the NRPA leads school groups to monitor the growth, taking measurements and relating the data back to Standards of Leaning and the environment.

Last week’s volunteers helped with the first step of this annual process, cleaning the “floats” — a PVC frame with net — and filling them with infant oysters ready for “planting.”

It was the third year Suffolk Police Department has partnered with NRPA on an environmental project, according to Elizabeth Taraski, the group’s executive director. The volunteers worked at a rapid pace, she noted, making it a very productive morning.

It was also clear that the police officers/civilians and other volunteers had fun. Who doesn’t enjoy blasting away mud with a power tool that squirts water under high pressure? I pity that joyless person.

The oyster float project was one of many activities around the city Friday driven by volunteers. Others took place at Western Tidewater Free Clinic, The Children’s Center, ForKids’ Suffolk House and Children’s Harbor.

In fact, the United Way of South Hampton Roads says that across Hampton Roads, more than 1,600 volunteers from 80 companies came together to complete 136 projects.

The program was established in 1991 to “promote the spirit of volunteerism, increase awareness of local human service organizations and demonstrate how people working together for the common good can accomplish great things.”

I know that at least one Day of Caring project in Suffolk last week hit the mark on all those points.