The Aberjona is a modest river, but it shapes East Woburn all the same — low ground that greens before anywhere else and holds a soft fog on summer evenings. AJM Grounds LLC keeps those flats and the streets that rise above them: cutting, edging, hauling away the leaves that pile in October, then swapping to plows and spreaders when the ground goes hard. Evening light lying flat across a freshly mown yard is a decent kind of payment for a long day. In winter the same properties are opened early, walks bare and gritted before anyone has to think about them. It is grounds work in the plain sense — a place looked after, week after week, storm after storm.