Sub-Domains within Physical Infrastructure

Seven sub-domains organize the physical-infrastructure architecture in PA-3. The decomposition is hybrid (population-cum-instrument): six substantive sub-domains organized by infrastructure system, plus a seventh that synthesizes the cross-cutting federal funding architecture under which the first six operate. The 2024-2026 period has been one of structural disruption across all seven — SEPTA's fiscal crisis with court order and capital-to-operating bridge; PWD's lead service line inventory and 2026 pilot replacement program with Green City Clean Waters trajectory shortfall against the 2036 endpoint; the Vision Zero Action Plan 2030 release with the underlying zero-deaths target revised from 2030 to 2050; Mayor Parker's December 19, 2025 Sanitation Department creation carved out of Streets; the AHERA Deferred Prosecution Agreement against SDP filed June 26, 2025 alongside the William Penn legislative response of $565M against an estimated ~$3.8B remaining adequacy gap; LWCF FY26 funding protected by Congress against the Administration's 43% diversion proposal; and the IIJA reauthorization inflection point at September 30, 2026 with no bill introduced as of May 2026. The recurring finding across all seven sub-domains is the structural mismatch between formal provision and actual experience — concentrated where the architecture's customer-side, sub-area, or cumulative-burden allocation leaves resolution outside federal-floor compliance financing. The four-dimensional anchor accountability framework (D7 real estate + D8 procurement + D9 fiscal + D10 employment) extended at D6 SD4 to the five-dimensional framework with the environmental-compliance dimension is referenced as established context; D13 intersects the framework at Penn's $100M SDP environmental-management pledge without architecturally extending it.