Capital Program Planning for Delaware Water Utilities

by | Oct 21, 2026

Delaware · Water & Wastewater Utilities

The lowest-lying state in America is planning water capital against a rising sea.

Saltwater creeping into coastal aquifers, PFAS limits with a 2029 clock, aging combined sewers in Wilmington, and nutrient pressure on the Inland Bays — every one of those forces reshuffles the projects on a Delaware utility’s list. Invizion helps Delaware water and wastewater utilities re-sequence a capital portfolio in a click — and defend every decision to the PSC, a city council, or ratepayers.

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The bottom line: Delaware is the lowest-lying state in the country, and its water future is being shaped from the coast inward — saltwater intrusion, PFAS with a 2029 deadline, aging combined sewers, and Inland Bays nutrients — just as a generation’s worth of SRF and BIL funding arrives. The utilities that win the decade will be the ones whose capital plans can absorb that volatility and stay defensible.
$1.81B1
Delaware’s estimated 20-year drinking water infrastructure need in EPA’s 7th needs survey (January 2021 dollars).
60 ft2
Delaware’s mean elevation — the lowest of any U.S. state, and the backdrop to sea-level rise and saltwater intrusion.
4543
Public water systems under state drinking-water oversight in Delaware.
$174.9M4
Federal Bipartisan Infrastructure Law water dollars directed to Delaware since 2022.

The Delaware Landscape

Four forces are moving your project list at once

None of these is theoretical, and none of them waits for your next budget cycle. In a state this flat and this coastal, the capital plan you approved last year may already be the wrong plan.

Supply — Coast & Aquifers

A rising sea, and salt moving into the wells

Delaware has the lowest mean elevation of any U.S. state, about 60 feet, and sea level along its coast has risen roughly 13 inches over the past century — at Bowers Beach, faster than anywhere else on the Atlantic coast.2 Sea level at the mouth of Delaware Bay has climbed about 7 inches in just the last 30 years, compounded by land subsidence across the Delmarva Peninsula.5

The capital consequence is saltwater intrusion. A 2025 assessment found salt water had reached irrigation ponds and a monitoring well near Dover, and the City of Dover already switches between aquifers seasonally to protect fresh supply.6 As one state hydrogeologist put it, once salt water moves in, it is very hard to get back out — so where the next well or source comes from is now a capital question.

Compliance — PFAS

A 4-ppt limit with a 2029 clock

EPA’s national drinking-water rule sets a 4 parts-per-trillion limit for PFOA and PFOS, with compliance required by 2029. In 2023–2024 sampling, about 6% of Delaware public-water samples contained PFAS and roughly 2.5% exceeded the concerning 14–21 ppt range — including detections at Suez/Veolia’s Stanton plant and an Artesian well, while New Castle’s system had already installed treatment.7

Filtration is not cheap: utilities have filed funding requests ranging from $200,000 to $90 million. Litigation is offsetting some of it — Artesian has received about $7.2 million from a 3M settlement and is crediting roughly $73 to each active Delaware customer — but the capital still has to be built and sequenced.8

Renewal — Aging Systems & Lead

Old pipe, combined sewers, and lead lines on the same clock

Wilmington runs a roughly 120-year-old collection system — about 300 miles of pipe, some 90% of it combined — so heavy storms send stormwater and sewage overflowing into the Brandywine and Christina Rivers.9 Statewide, EPA pegs Delaware’s 20-year drinking water need near $1.81 billion.1

On top of renewal, lead service line inventory and replacement is now a funded mandate flowing through the state’s drinking-water program.3 New obligations don’t replace the old backlog — they stack on it, and something on the list has to move.

Water Quality — Inland Bays

Nutrient pressure on Sussex County’s waters

Delaware’s Inland Bays — Rehoboth, Indian River, and Little Assawoman — remain among the most nutrient-enriched estuaries in the country, driven by nitrogen and phosphorus from wastewater, septic systems, and runoff. DNREC’s Pollution Control Strategy pushes systems and developments toward advanced treatment and reduced loading.10

For utilities in fast-growing coastal Sussex, that means wastewater capacity, treatment upgrades, and sewer extensions to retire septics — capital that competes directly with drinking-water renewal for the same dollars.

Who Runs Delaware’s Water

A small state where investor-owned utilities carry a large share

Unlike most states, Delaware’s water is delivered heavily by regulated private companies alongside a handful of municipal systems. Artesian and Tidewater (a Middlesex Water subsidiary) answer to the Public Service Commission; Wilmington, Dover, and Newark answer to their councils.

Municipal utilities

Rates set by city council · capital approved by governing bodies

City of Wilmington Water & Sewer ~300 mi of combined sewers, ~120 yrs old9
City of Dover ~40,000 residents · seasonal aquifer switching6
New Castle Municipal Services Commission Installed PFAS treatment since 20147
City of Newark University-town municipal system
Small towns & sanitary districts Kent & Sussex — where funding gaps hit hardest

Investor-owned utilities

Rates & capital recovery regulated by the Delaware PSC

Artesian Water Company 80,100 metered customers · ~1,491 mi of main11
Tidewater Utilities (Middlesex Water) ~60,000 retail customers, 3 counties12
Veolia / Suez Water Delaware Stanton-area treatment & PFAS response7
White Marsh Environmental Systems ~4,500 customers, Kent & Sussex12

Artesian invested roughly $40.5 million in water and wastewater infrastructure in the first nine months of 2025 alone.13

Rate-Setting & Oversight

Every capital dollar has to be defensible

Whether you answer to the Public Service Commission or a city council, the question is the same: why this project, why now, why at this cost? Delaware’s oversight bodies are asking it harder than ever.

  • Delaware Public Service Commission (PSC) regulates rates and capital recovery for investor-owned utilities. Artesian’s 2023 case — its first rate request in nine years — opened at 23%, ran through interim rates, and settled at a 15% increase approved in June 2024.14
  • The Division of the Public Advocate negotiates on behalf of ratepayers — it shaped the Artesian settlement and reviewed the PFAS-settlement customer credit before the PSC approved it.8
  • DNREC and the DHSS Office of Drinking Water hold Safe Drinking Water Act primacy — PFAS monitoring, lead service line inventories, and the compliance capital that follows.3
  • City councils & boards approve municipal capital plans in public, in front of ratepayers — Wilmington’s combined-sewer and Clean Waterways program among them.9

Funding On The Table

The money is moving — can your plan absorb it?

Delaware utilities have more capital funding available than they’ve had in a generation. The constraint is no longer only dollars — it’s readiness: which projects are shovel-ready, which qualify, and how the timing lines up with everything else on the list.

  • Drinking Water State Revolving Fund (FFY25) — a $10.9M base capitalization grant plus roughly $24.9M in IIJA supplemental funds and $7.9M dedicated to emerging contaminants such as PFAS.3
  • $62.28M in IIJA drinking-water funding was allotted to Delaware in 2023 for lead line replacement, PFAS, and system upgrades.15
  • $20.9M announced for FY25 — more than $12.2M through the Clean Water SRF and more than $7.6M for drinking-water emerging contaminants.16
  • $174.9M in total BIL water dollars has flowed to Delaware since 2022, including a February 2024 tranche of more than $42M across drinking water, wastewater, and stormwater.4

Where Invizion Fits

Turn a moving Delaware picture into a defensible capital plan

Invizion is scenario-based capital portfolio optimization built for water utilities. When the supply picture shifts, a mandate lands, or a grant comes through, you don't re-plan by hand for weeks — you model it and decide with a record you can stand behind.

1

Model the “what-if” before it's forced on you

A new mandate, a failed main, a grant with a deadline — build the scenario and see the impact on the whole portfolio, side by side with today's plan.

2

Re-sequence 500 projects in a click

When priorities move, Invizion re-orders the portfolio automatically — accelerating, stretching, or deferring projects against the constraints you set, not weeks of spreadsheet surgery.

3

Give regulators or your board a defensible record

Every prioritization and trade-off is captured. When you're asked “why this project, why now,” the answer is documented — not reconstructed after the fact.

Delaware Water, In Brief

Questions Delaware utility leaders are asking

Short, sourced answers — the same facts we’ll dig into on a call, in the context of your system.

Is Delaware really the state most exposed to sea-level rise?
By elevation, yes — Delaware has the lowest mean elevation of any U.S. state, about 60 feet, and state assessments project 8–11% of its land could be inundated by 2100 depending on the scenario. Sea level at the mouth of Delaware Bay has risen roughly 7 inches in 30 years, and at Bowers Beach the rate is the fastest on the Atlantic coast. For utilities, that translates directly into saltwater-intrusion risk for coastal wells.25
What does the PFAS rule mean for Delaware utilities’ capital plans?
EPA’s rule caps PFOA and PFOS at 4 parts per trillion with compliance due by 2029. About 6% of Delaware samples in 2023–2024 contained PFAS and roughly 2.5% exceeded the concerning range, with detections at systems including Suez/Veolia and Artesian. Treatment cost estimates have ranged from $200,000 to $90 million per utility, and settlement dollars — such as Artesian’s ~$7.2M from 3M — offset only part of it.78
Who sets my utility’s water rates in Delaware?
The Delaware Public Service Commission regulates rates and capital recovery for investor-owned utilities such as Artesian Water and Tidewater Utilities, with the Division of the Public Advocate representing ratepayers. Municipal systems — Wilmington, Dover, Newark — set rates through their own councils. Artesian’s most recent case settled at a 15% increase approved in June 2024, its first in nine years.14
How much funding is available to Delaware water utilities?
A lot, by historical standards. Delaware’s FFY25 Drinking Water SRF carried a ~$10.9M base grant, ~$24.9M in IIJA supplemental funds, and ~$7.9M for emerging contaminants; a separate 2023 IIJA allotment totaled $62.28M; and about $174.9M in total BIL water dollars has reached the state since 2022. The gating factor is project readiness and eligibility, not the availability of dollars.3154
What’s happening with saltwater intrusion?
A 2025 assessment found salt water reaching irrigation ponds and a monitoring well near Dover, though deeper aquifers remained largely protected. The City of Dover already shifts between aquifers seasonally to protect fresh supply during the growing season, and the Delaware Geological Survey is expanding monitoring. For utilities, it makes long-term source planning — new wells, treatment, interconnections — a live capital decision rather than a distant one.6
How does Invizion help Delaware water utilities plan capital?
Invizion is scenario-based capital portfolio optimization for water utilities. It lets you model how a PFAS deadline, a saltwater-intrusion source project, a new SRF award, or a PSC rate outcome reshuffles your whole project list; re-sequence the portfolio automatically against the constraints you set; and keep a defensible record of every trade-off for the PSC, your council, the Public Advocate, or ratepayers. The best next step is a short first meeting to look at it against your own program.

Go Deeper

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About the Author

GB

Guy Barlow

President, Invizion

Guy Barlow leads Invizion, a capital lifecycle management platform for water and wastewater utilities. He has spent two decades at the intersection of utility capital programs, funding, and analytics, helping utilities make faster, more defensible capital decisions.

Start The Conversation

See what a defensible capital plan looks like

Book a 20-minute first meeting. We'll talk through the forces reshaping your capital program and show how Invizion helps you keep the plan current and defensible — no slides, no pressure.

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This briefing was last reviewed September 2026.

Sources

  1. U.S. EPA, 7th Drinking Water Infrastructure Needs Survey and Assessment (Exhibit 1.4) — Delaware 20-year need $1,809.9M (January 2021 dollars), 2023. epa.gov
  2. University of Delaware Research Magazine, “America’s flattest state prepares for the future” — lowest mean elevation (60 ft), ~13 in sea-level rise/century, Bowers Beach fastest on the Atlantic coast, 8–11% inundation by 2100. udel.edu
  3. Delaware Drinking Water State Revolving Fund, Intended Use Plan FFY25 — ~454 public water systems; base cap grant $10.935M, IIJA supplemental $24.898M, emerging-contaminants $7.857M; lead service line inventories, 2025. dhss.delaware.gov
  4. U.S. EPA news release, “$42 million for Delaware drinking water, wastewater and stormwater” — $174.9M total BIL water investment in Delaware since 2022, February 2024. epa.gov
  5. Partnership for the Delaware Estuary, State of the Estuary — ~7 in sea-level rise at the mouth of Delaware Bay over 30 years; Delmarva land subsidence, ~1 ft or more by 2050. delawareestuary.org
  6. Spotlight Delaware, “Saltwater intrusion requires underground compromise in Kent County” — 2025 findings near Dover; City of Dover (~40,000) seasonal aquifer switching; DGS monitoring, December 2025. spotlightdelaware.org
  7. Delaware Public Media, “EPA data shows most Delaware drinking water meets federal PFAS standards, but concerns remain” — 4 ppt limit, 2029 compliance; ~6% of samples with PFAS; Suez Stanton 24.4 ppt, Artesian 23.1 ppt; New Castle treatment; $200K–$90M requests, October 2024. delawarepublic.org
  8. Artesian Water Company / GlobeNewswire — ~$7.2M received from 3M PFAS settlement; ~$73 credit per active Delaware customer; PSC-approved, November 2025. globenewswire.com
  9. Wilmington Water Utility, “Combined Sewer Overflows (CSOs)” — ~120-year-old system, ~300 miles of pipe, ~90% combined, overflows to the Brandywine and Christina Rivers, 2025. wilmingtondewater.gov
  10. DNREC / Delaware Center for the Inland Bays — nutrient enrichment of Rehoboth, Indian River, and Little Assawoman Bays; Inland Bays Pollution Control Strategy, 2024–2025. inlandbays.org
  11. Artesian Resources Corporation, Form 10-K (FY2024) — 80,100 metered customers in its largest connected system; ~1,491 miles of transmission and distribution main; 9.4B gallons distributed in 2024. artesianwater.com
  12. Middlesex Water Company, “Tidewater Utilities, Inc.” — ~60,000 retail customers across New Castle, Kent, and Sussex Counties; White Marsh ~4,500; largest private supplier south of the C&D Canal, 2025. middlesexwater.com
  13. Artesian Resources Corporation, Third Quarter and Year-to-Date 2025 results — ~$40.5M invested in water and wastewater infrastructure year-to-date, October 2025. artesianwater.com
  14. Cape Gazette, “Public Service Commission approves Artesian water rate increase” — 15% increase approved June 12, 2024 (opened at 23%, interim ~14%), first increase since 2014; 9.50% ROE, June 2024. capegazette.com
  15. U.S. EPA news release — $62.28M for Delaware drinking-water infrastructure under the IIJA (lead lines, PFAS, upgrades), April 2023. epa.gov
  16. U.S. EPA news release, “$20.9 million for water infrastructure in Delaware” — >$12.2M Clean Water SRF and >$7.6M drinking-water emerging contaminants, October 2024. epa.gov