OpenAQ handles access, harmonization of data from multiple sources and interactive map for researchers and communities. The records it holds — PM2.5, PM10 and SO₂ — sit under its own export limits, retention rules and terms governing what you may do with your own information. Most of what a firm runs was never designed to hand its data back. Milemarker's ingestion layer connects to OpenAQ and lands what your agreements permit into a Snowflake environment your firm owns and administers, normalized into a model that stays stable even when the systems around it change. That means OpenAQ stops being a corner of the business nobody can report on. Its data joins your custodial, CRM, billing and planning sources under one set of rules — row-level entitlements, PII masking and SOC 2 Type II controls you set, rather than the scope any one vendor happens to offer.