Water Testing in Delaware
Find a state-certified drinking water laboratory, see what to test for first, and learn how to read your results.
Getting your water tested in Delaware
Drinking water labs serving Delaware are certified by the Delaware Health and Social Services under the Office of Drinking Water Laboratory Certification Program. Certification is a federal requirement under 40 CFR 142 — only state-certified labs can produce results that count for regulatory, real-estate, or legal purposes. Across 43 Delaware cities tested by WaterVerge, our data shows 1 city with lead exceeding the EPA action level, 21 cities with PFAS detections (13 above the 2024 limits), 40 cities with health-based violations on record. That context shapes which tests are worth prioritizing. For peace-of-mind testing or filter selection, a reputable mail-in kit will do. For real-estate transactions, well permits, landlord disputes, school testing, or any result that has to be defensible, you must use a state-certified laboratory.
Should you test your water?
What to test for in Delaware
Recommendations driven by water-quality patterns we observe in Delaware cities. Your specific situation may require additional analytes.
- 01
Lead
1 Delaware city has lead exceeding the EPA action level. Lead in tap water comes from service lines and home plumbing — your tap may have it even when the system overall is fine.
Lead in Delaware data → - 02
PFAS
PFAS "forever chemicals" detected in 21 Delaware cities, 13 above the 2024 EPA limits. Look for labs accredited to EPA Method 533 or 537.1.
PFAS in Delaware data → - 03
Nitrate & bacteria
86% of tested Delaware cities rely on groundwater. Wells and ground-sourced systems should screen for nitrate, arsenic, and total coliform regularly.
What it costs & how long it takes
Mail-in kits vs. state-certified labs
Mail-in test kits
- Best for: general curiosity, picking a filter, screening for a single concern, comparing tap to filtered water.
- Not for: real-estate transactions, legal disputes, well permits, anything where the result needs to be defensible.
- Most kits use accredited partner labs but the chain-of-custody isn't certified. Cheaper, simpler, fine for personal use.
State-certified labs
- Best for: regulatory compliance, well permits, legal evidence, landlord disputes, school/daycare testing, formal complaints to your utility.
- Tradeoffs: more expensive, may require courier/dropoff with strict timing, sample bottles coordinated in advance.
- The directory above lists every lab Delaware has formally certified. Pick from this list if the result needs to count.
How to pick the right lab
- 01Confirm certification scope. A lab can be certified for some methods and not others. Verify they're accredited specifically for what you want tested (e.g. EPA 533 for PFAS, EPA 200.8 for lead).
- 02Use the official sample bottles. Labs ship pre-cleaned, pre-preserved bottles. Don't substitute — improper containers invalidate results.
- 03Mind the hold times. Bacteria samples ~30 hours. Metals 6 months. VOCs 14 days. Plan shipping accordingly.
- 04Get a written report, not just numbers. Reputable labs include MDL/MRL (detection limits), regulatory limits, and method codes — you need these to interpret results.
- 05Confirm the result will hold up. If it's for a real-estate sale, court case, or regulatory dispute, the lab must be state-certified and follow chain-of-custody procedures.
Look up your city in Delaware
All 43 cities →Before testing, check what's already on record for your local water system — it tells you what to focus on.
Explore what's been measured in Delaware
Frequently asked questions about water testing in Delaware
Where can I get my water tested in Delaware?
Delaware certifies drinking water labs through the Delaware Health and Social Services (Office of Drinking Water Laboratory Certification Program). The official directory is hosted at dhss.delaware.gov. Use a state-certified lab if you need results that hold up for legal, real-estate, or regulatory purposes.
How much does it cost to test water in Delaware?
A single-contaminant test (lead, nitrate, bacteria) typically runs $25–$60. A general panel covering common parameters is usually $50–$150. A comprehensive panel including PFAS or VOCs runs $250–$450 or more depending on the analyte list. Mail-in kits are cheaper but may not be accepted as legal evidence.
What contaminants should I test for first?
Based on Delaware water-quality data, prioritize: Lead; PFAS; Nitrate & bacteria. Your specific home and source water determine the rest — homes built before 1986 should always test for lead.
Do I need a state-certified lab, or is a mail-in kit enough?
For peace-of-mind testing or to inform a filter purchase, a reputable mail-in kit is fine. For real-estate transactions, well permits, landlord disputes, or any result you need to defend, you must use a state-certified drinking water laboratory. Certified labs follow EPA-approved methods and are audited by the state.
How do I collect a water sample correctly?
The lab provides specific bottles and instructions — follow them exactly. For lead, run a "first draw" sample (water that has sat in pipes 6+ hours). For bacteria, sterilize the tap and avoid touching the bottle interior. For VOCs, fill bottles to the brim with no headspace. Improper collection is the #1 cause of unreliable results.
How long do results take?
Most chemical tests return in 5–10 business days. Bacterial tests are quicker (24–48 hours after the lab receives the sample). PFAS and specialty methods can take 2–4 weeks. Rush turnaround is usually available for an extra fee.