OpenAI 2026 hackathon

TapCheck

Type your ZIP code, get a plain-language report on what's actually in your tap water; violations, contaminants, health context, and what filter (if any) you need.

Solo project by Dwain Prendergast · 1 likes · 4 comments

Archive position — measured, not model output

1 like on Devpost

506 of the 7,856 archived projects have more likes, and 1,758 share exactly 1 — so this project's #2,034 place in the like-ranked listing is a tie-break inside that group, not a ranking.

Projects (log scale)

1
10
100
1k
10k
05,592
11,758
2285
3–4132
5–975
10+14

Likes on Devpost. ▲ marks this project's group.

Show the figures
LikesProjectsShare of archive
05,59271.2%
11,75822.4%
22853.6%
3–41321.7%
5–9751.0%
10+140.2%
Devpost like counts for all 7,856 archived projects, captured when this archive was built.

Executive Summary

What the company appears to be

TapCheck is a self-reported water quality reporting tool that uses EPA data and AI to generate plain-language reports for ZIP codes. The description states it was built as a hackathon project with a single founder, Dwain Prendergast.

What changed

The project evolved from an idea about making EPA water quality reports readable to a functional web application that processes EPA data through GPT-5.6 and presents results in structured, citable formats.

The single most important open question

Is there any evidence of actual user adoption or traction beyond the hackathon submission? The description makes no claims about revenue, customers, or usage metrics.

Back to contents

What The Product Actually Is

The description states that TapCheck is a web application that:

  • Takes a ZIP code as input
  • Generates a plain-language water quality report in ~10 seconds
  • Uses live EPA SDWIS data
  • Provides letter grades and summaries for water systems
  • Shows per-contaminant cards with health effects and legal limits
  • Offers filter recommendations (activated carbon vs reverse osmosis vs "you don't need one")
  • Includes dedicated tabs for fish, plants, and pets
  • Has honest empty states that acknowledge when data is missing

The product is described as built end-to-end using Codex and GPT-5.6 during a Build Week hackathon.

Evidence The author's own write-up describes the functionality.

Inference The tool appears to be a data aggregation and interpretation platform, not a direct service provider or subscription business.

Back to contents

Positioning & Claim Evolution

The description states that TapCheck was inspired by the problem of "14 pages long" EPA annual quality reports that are unreadable to average users. It positions itself as solving this by providing:

  • Plain-language reporting
  • Structured outputs with citations
  • Health context for contaminants
  • Filter recommendations
  • Specialized content for non-human users (fish, plants, pets)

The claim evolution appears to be from a personal frustration with EPA reports to a tool that makes them accessible and actionable.

Evidence The author's own write-up describes the inspiration and positioning.

Inference The positioning is focused on accessibility and trustworthiness of public health data, not commercialization or monetization.

Back to contents

Target Customer & ICP

The description states that TapCheck serves:

  • Residents who want to know if their tap water is safe
  • Users interested in understanding what's actually in their tap water
  • People concerned about contaminants like chloramine
  • Pet owners and gardeners who need information about water effects on fish, plants, and animals

It also mentions "50 million Americans" served by systems with recent violations, though this is not a stated target customer but rather a context for the problem.

Evidence The author's own write-up describes the intended audience.

Inference The ICP appears to be general public users concerned about water quality, particularly those who find EPA reports inaccessible or confusing.

Back to contents

Business Model & Pricing Evidence

The description does not state any business model or pricing information. It only describes the product functionality and how it was built.

Evidence Not evidenced.

Inference Based on the description alone, there is no indication of monetization, subscriptions, or paid features.

Back to contents

Technical & Delivery Signals

The description states that TapCheck was built with:

  • Codex (used for reverse-engineering APIs and scaffolding)
  • GPT-5.6 (as interpretation layer with structured outputs)
  • Next.js, React, Node.js, TypeScript
  • Vercel deployment
  • EPA Envirofacts API (SDWIS data)
  • Aggressive caching due to federal API response times

It also mentions that the tool uses JSON schema for structured outputs and cites source records to prevent hallucination.

Evidence The author's own write-up describes the technical stack and approach.

Inference The technical approach suggests a data-driven, AI-enhanced product with strong focus on accuracy through citation.

Back to contents

Traction & Maturity Signals

The description states that this was a hackathon project built during Build Week. It mentions:

  • Shareable report URLs
  • Designed empty states
  • Live deployment
  • A feature nobody else has (telling you whether tap water will kill your goldfish)
  • Accomplishments that were proud of: complete product, not proof of concept

However, there is no evidence of revenue, customers, or usage metrics beyond the hackathon submission.

Evidence The author's own write-up describes the project as a hackathon submission.

Inference There is no evidence of traction or maturity beyond the initial prototype.

Back to contents

Competitive Context

The description does not mention any competitors or competitive landscape. It only states that "nobody else has" the feature of telling users whether their tap water will kill goldfish.

Evidence Not evidenced.

Inference The competitive context is unknown, but the unique selling point appears to be the specialized content for non-human users.

Back to contents

Key Risks & Red Flags

  • No traction or revenue evidence: The project was submitted as a hackathon entry with no indication of adoption or monetization.
  • Single founder: Only one team member listed (Dwain Prendergast).
  • Unverified health claims: While the tool cites EPA records, it's unclear how it validates or verifies the health information presented.
  • Dependency on public data: Reliance on EPA data that may be inconsistent or outdated.
  • No business model: No indication of how the product will generate revenue or sustain itself beyond a hackathon prototype.

Evidence The author's own write-up and lack of any external validation.

Inference These are risks based on the limited evidence provided, not confirmed issues.

Back to contents

Diligence Questions To Ask The Founders

  1. What is your plan for scaling beyond the hackathon prototype?
  2. How do you intend to validate or verify the health information presented in the reports?
  3. Have you considered how to monetize this product if it gains traction?
  4. What are the legal implications of providing health-related information based on public data?
  5. Are there any partnerships or integrations with utilities or health organizations planned?
  6. How do you plan to handle updates to EPA data and ensure accuracy over time?

Evidence Not evidenced.

Inference These questions arise from the lack of evidence around traction, monetization, and risk management.

Back to contents

Investment/Partnership Verdict

The description states that TapCheck was submitted as a hackathon project. There is no evidence of revenue, customers, or traction beyond the initial prototype. The tool appears to be a proof-of-concept rather than a commercial product.

Evidence The author's own write-up describes it as a hackathon submission with no mention of commercialization or adoption.

Inference Based on the self-reported information, there is insufficient evidence to support an investment or partnership decision at this stage.

Back to contents

Source

Submitted to the OpenAI 2026 hackathon on Devpost. Project home on DevPost.

The analysis above was generated by a language model from the project's own one-line description. It is not independent research and contains no verified traction, revenue or customer data.