Hillsborough County's SE County Landfill is filling faster than any existing facility can burn — the Q3 2026 authorization window is the only action required to preserve a 2028 solution.
Hillsborough County generates approximately 2,545 TPD of manufacturing feedstock — unsorted MSW, WTE combustion ash, biosolids, and tires — across a system that has recorded a 38% single-year tonnage increase and is expanding landfill cell elevation to absorb the overflow. The county's Solid Waste Master Plan runs to 2065 and contains no new greenfield landfill siting. The Reworld™ Resource Recovery Facility operates at its 1,800 TPD permitted capacity. There is no structural relief mechanism in development.
One action preserves all optionality: authorize the Community Feasibility Study by Q3 2026.
The county currently pays a verified $110/ton processable disposal rate for its primary waste stream, and a blended rate of approximately $95/ton across all streams. These rates have increased structurally — 3% annual tonnage growth since 2015, active landfill capital investment ongoing, and no competing infrastructure in the procurement pipeline. State A is a cost escalation trajectory, not a stable operating condition.
Carbotura offers a 30-year Commercial Offtake Agreement under which the county delivers feedstock to an ACM facility at $100/ton starting TMC Fee — below its own verified primary disposal rate from day one. The Carbotura SPV finances, builds, and operates the facility. The county contributes zero capital. Beginning in Month 13, the county receives a Circular Royalty structured as a percentage of the TMC Fee paid 13 months prior: 120% of Year 1 TMC, escalating one percentage point per year for the full 30-year term.
At a T0 of Q2 2026, Phase Initial (400 TPD) reaches COD in Q2 2028 — 24 months from authorization. The Q3 2026 Feasibility Study deadline is the only action required to hold this schedule. It is an information-gathering step, not a contract commitment.
The royalty structure has three distinct periods that must not be combined. Circular Royalty payments begin 13 months after the corresponding TMC Fee payment, on a rolling monthly basis. This is not an annual switch-on event — each TMC Fee payment generates a corresponding Circular Royalty payment 13 months later.
Gross cost displacement is quantified separately from Circular Royalty cash flow. Full net fiscal position reflects both.
| Parameter | Value | Source |
|---|---|---|
| Addressable feedstock — Hillsborough County primary | 1,745 TPD · 637,000 TPY | ESTIMATED — EPA 4.9 lbs/cap/day basis; component rates verified |
| Total regional addressable (Phase Expanded) | ~2,545 TPD · ~929,000 TPY | ESTIMATED — includes Pasco County + regional C&I via CSX rail |
| Current disposal cost — primary stream | $110.00/ton (processable MSW, municipal rate) | VERIFIED — HC Rate Resolution, effective October 1, 2024 |
| Current disposal cost — blended (FWDC) | ~$95.00/ton | ESTIMATED — modeled; component rates verified |
| TMC Fee — Year 1 | $100.00/ton · +2.5%/year | ESTIMATED — formula floor; below verified primary rate |
| Gross cost displacement | +$10/ton vs. primary rate · −$5/ton vs. blended FWDC | ESTIMATED — quantified separately from royalty |
| Circular Royalty — Year 1 | $0 — pre-royalty period (Months 1–12) | Fixed contractual structure |
| Circular Royalty — lag | 13 months after corresponding TMC Fee payment · rolling monthly | Fixed — Carbotura standard parameters |
| Net position — Year 2 (Phase Initial) | +$17.50/ton · +$2,555,000/year | ESTIMATED — royalty $120/ton less TMC $102.50/ton |
| Net position — Year 30 (Phase Initial) | +$90.84/ton · +$13,262,640/year | ESTIMATED |
| Cumulative 30-year royalty (Phase Initial) | ~$180,000,000 | ESTIMATED |
| First royalty payment | July 2029 (13 months after Q2 2028 Phase Initial COD) | ESTIMATED — Carbotura standard schedule |
| County capital obligation | $0 — BOO structure; SPV provides all capital | Fixed — COA structure |
| SE County Landfill pressure | 38% single-year tonnage increase (2024); cell expansion underway; no new greenfield siting | VERIFIED — Director Tramel, Bay News 9, May 2025 |
| Procurement decision deadline | Q3 2026 — Feasibility Study authorization | Derived from Carbotura standard 24-month construction schedule |
| Phase Initial COD | Q2 2028 (T0 + 24 months) | ESTIMATED — Carbotura standard schedule |
| Phase Expanded capacity | 2,000 TPD · 730,000 TPY · Q2 2031 | ESTIMATED |
| Direct employment — Phase Expanded | ~155 FTE direct · ~465 indirect | ESTIMATED — Carbotura standard parameters |
The specific instrument that creates irreversibility is the Southeast County Landfill cell capacity commitment — the capital contract for additional airspace at 15960 County Rd. 672, Lithia. Once that capital is committed, the State A trajectory is locked for the life of the cell (8–12 years), and the institutional momentum it creates works against a structural alternative. Every quarter that Feasibility Study authorization slips after Q3 2026 shifts Phase Initial COD by an equivalent quarter — at Phase Initial volume (146,000 TPY), each quarter's delay accumulates approximately $1,460,000 in disposal costs that would otherwise be displaced by the TMC Fee structure. At Phase Expanded scale, the same delay costs nearly $7.3M per quarter in deferred displacement. The royalty stream that begins in July 2029 does not accrue retroactively — every quarter of delay is a quarter of royalty income permanently forfeited.