Does Holly Springs, NC Tap Water Have Pesticides in It?

Triangle Waterworks · informational guide

Direct answer: Yes — unlike Raleigh, Cary, or Apex, Holly Springs draws from the Cape Fear River through Harnett Regional Water, and Harnett's 2024 report lists a detected herbicide: simazine at 0.130 ppb, safely under the legal limit with no violation. Different watershed, different answer. A carbon stage removes it, along with the chlorine, chloramine, and disinfection byproducts also present in Holly Springs' water.

Does Holly Springs, NC Tap Water Have Pesticides in It?

Yes, in a small but real, verified amount. Holly Springs' water source is the Cape Fear River, processed at the Harnett County water treatment plant and supplied through Harnett Regional Water, per the Town's own Infrastructure page. Harnett Regional Water's 2024 Water Quality Report lists simazine at 0.130 ppb — a genuine detection, well under its 4 ppb legal limit, with no violation.

That's a different answer than most Triangle towns give, and the reason is the water source itself. See the fuller picture of water treatment in Holly Springs for what that means for a typical home.

Why Is Holly Springs' Water Different From Raleigh's or Cary's?

Because it isn't on the same system. Raleigh, Cary, Apex, and Morrisville all draw from either Raleigh Water or the Jordan Lake-fed Cary/Apex Water Treatment Facility, and none of those systems' current reports show a pesticide or herbicide row at all. Holly Springs draws from an entirely different watershed and a different treatment plant.

That's why the Raleigh-area non-detect doesn't automatically carry over to Holly Springs. See how pesticide and herbicide results compare across Triangle NC water systems for the fuller picture — different sources genuinely produce different results.

What Did Holly Springs' Supplier Actually Detect?

A real detection, clearly documented. Harnett Regional Water's 2024 report lists simazine at 0.130 ppb, sampled January 3, 2024, against a legal limit (MCL) of 4 ppb — well under the limit, with no violation reported. The report's own "likely source of contamination" column attributes it to herbicide runoff.

This is the only detected pesticide or herbicide anywhere in Triangle Waterworks' verified source documents for the region. It's genuinely useful information for a Holly Springs homeowner specifically, since it doesn't show up in Raleigh's or Cary's reports at all.

Does Being Under the Legal Limit Mean It's Not Worth Filtering?

No — a compliant, below-limit result is exactly the case for filtering it, not a reason to skip that step. Simazine at 0.130 ppb against a 4 ppb limit is legally fine and genuinely detected at the same time, and both facts matter together.

A carbon filtration stage removes herbicides like simazine directly, rather than relying on staying under a legal number to keep it out of your glass. For a Holly Springs home on the Harnett Regional Water connection, that's a real, address-specific reason to filter.

Is Holly Springs' Water Hard?

It depends on which end of the range you're looking at, and both ends land in the same classification. The Town of Holly Springs' own Drinking Water page states the water is "moderately soft and usually averages between 30-50 mg/L hardness as calcium carbonate or 1.75-2.92 grains of hardness per gallon."

On the WQA/Hach scale Triangle Waterworks uses — the same one the Hach Total Hardness Test Kit, Model 5-B reads out on — that entire 1.75 to 2.92 gpg range falls in the slightly hard band. The Town's own "moderately soft" label and our "slightly hard" label describe the same numbers on different scales; neither contradicts the other. Slightly hard still means calcium and magnesium accumulate on fixtures and inside a water heater over years.

What Else Shows Up Besides the Herbicide?

Real disinfection byproducts, on the same Harnett Regional Water report. Total trihalomethanes (TTHM) reach a highest running annual average of 40.8 ppb (limit 80), with individual zone results ranging 13.7 to 52.0 ppb. Haloacetic acids (HAA5) reach a highest LRAA of 29.6 ppb (limit 60), with zone results from 11.5 to 51.9 ppb.

EPA's National Primary Drinking Water Regulations table lists TTHM's potential long-term health effect above the legal limit as "Liver, kidney or central nervous system problems; increased risk of cancer," and HAA5's as "Increased risk of cancer."

Both figures are compliant — Harnett Regional Water isn't violating anything. But the legal limit is a ceiling EPA set at the edge of its own acceptable risk, not a guarantee everything under it deserves no attention. Harnett's report also shows a chloramine running annual average of 2.64 ppm, plus a period run on free chlorine only — covering the month of March in that reporting year — which is a normal maintenance step that can change how the water tastes while it's in effect.

Holly Springs vs. a Raleigh-Supplied Triangle Town

What Should a Holly Springs Homeowner Actually Do With This?

Take the herbicide detection seriously as information, not as an alarm — it's compliant, and it's also genuinely there. Whether a filter is worth it for your specific home is worth its own look, and testing your own tap's hardness confirms where you actually fall in that 1.75–2.92 gpg range. A carbon stage addresses the herbicide, the disinfection byproducts, and the chlorine taste together; softening resin addresses the hardness.

FAQ

I live in Holly Springs and just read that our water has a detected herbicide — is that dangerous? No, not as a violation — simazine at 0.130 ppb sits well under the 4 ppb legal limit, and Harnett Regional Water reported no violation. It is a genuine detection, though, which is a real, specific reason to run Holly Springs water through carbon filtration rather than assume compliant means nothing is there.

Why does my Holly Springs water test different than what I've read about Raleigh or Cary? Because Holly Springs isn't on either system — it draws from the Cape Fear River through Harnett Regional Water, a completely different source and treatment plant than Raleigh Water or the Cary/Apex Jordan Lake facility. Different watersheds produce different results, and Harnett's report is the one that actually applies to a Holly Springs tap.

Is Holly Springs' water hard or soft — the Town says moderately soft, but I've also seen "slightly hard"? Both are accurate; they're just different scales for the same numbers. The Town's own page states 1.75 to 2.92 grains per gallon and calls that "moderately soft," while the WQA/Hach scale Triangle Waterworks uses classifies that identical range as "slightly hard."

Should I wait until a herbicide level exceeds the legal limit before doing anything about it? No — a compliant result and a worthwhile carbon upgrade aren't in conflict. Simazine at 0.130 ppb is legally fine today in Holly Springs' Harnett-supplied water, and it's still a real, verifiable reason to filter, since a carbon stage removes it directly instead of relying on staying under a number.

Why does my water in Holly Springs sometimes smell stronger of chlorine for a few weeks? That's Harnett Regional Water switching from its usual chloramine to free chlorine only for a stretch — its 2024 report records that period as covering the month of March that year. It's a normal system-wide maintenance step, and free chlorine tends to have a more noticeable smell than chloramine while it's in effect. Timing can shift, so check Harnett Regional Water's own announcements rather than assuming a fixed calendar.

What actually removes a detected herbicide like simazine from my Holly Springs water? A carbon filtration stage, which is built to remove herbicides, chlorine and chloramine taste, and disinfection byproducts directly rather than relying on a legal limit to keep them out. An all-in-one system pairs that carbon stage with softening resin for the hardness side in one install.

See What's Actually Coming Out of Your Holly Springs Tap

Holly Springs' water source is genuinely different from most of the Triangle, and its herbicide detection is the clearest example of why. Take the 60-second water quiz to see how an all-in-one system fits your Holly Springs home.

Sources

• Harnett Regional Water — 2024 Water Quality Report
• Town of Holly Springs — Drinking Water
• Town of Holly Springs — Infrastructure
• EPA — National Primary Drinking Water Regulations