Do you need to test your drinking water for nitrate and nitrite?

Overview:

  • Dellavalle Laboratory is an ELAP (Environmental Laboratory Accreditation Program) certified laboratory and can analyze your drinking water for nitrate and nitrite to comply with the Irrigated Lands Regulatory Program (ILRP).

The purpose of the drinking water monitoring portion of the ILRP is to identify drinking water wells that have nitrate-nitrogen + nitrite-nitrogen concentrations above the drinking water limit of 10 mg/L and to notify the water users.

Sampling Frequency:

The sampling frequency depends on the level of nitrate-N + nitrite-N levels in your sample.

If the sum of nitrate-N + nitrite-N is:

  • Below 8 mg/L: Sample for three consecutive years. If results are below 8 mg/L for all three years, then sample once every 5 years.
  • Between 8 mg/L and 10 mg/L: Sample ever year.

Above 10 mg/L: Notify the water users and no additional sampling is required.

Monitoring Calendar:

Beginning January 1, 2019

Beginning January 1, 2020

  • Tulare Lake Basin
  • Kings River Watershed Coalition Authority
  • Westlands Water Quality Coalition
  • Kaweah Basin Water Quality Coalition
  • Tule Basin Water Quality Coalition
  • Cawelo Water District Coalition
  • Westside Water Quality Coalition
  • Kern River Watershed Coalition Authority

Buena Vista Coalition

Beginning January 1, 2021

Beginning January 1, 2022

Filling out paperwork:

Water Board Drinking Water Well information:

  • This form allows the laboratory results to be uploaded to the State’s GeoTracker database. It is important to clearly fill out this form or there may be some issues uploading the lab data to GeoTracker. When naming the well keep it simple and easy to remember. The well ID can have 10 characters or less. Once results are uploaded to the GeoTracker website, the well ID cannot be changed.
  • Assessor’s Parcel Number (APN)
  • You can find your APN by going to your County Assessor’s webpage and searching by address.
  • How to find GPS Location
  • Dellavalle Work Request:
  • Please fill out all the highlighted areas and the chain of custody (see video above). “Well ID/Field Point Name” and Coalition Member ID must be the same on both forms.

How to Sample:

Bottles and equipment:

  • 250 mL unpreserved plastic sampling bottle.
  • Ice chest and ice.

Procedure:

  • If the well is not frequently used, run water for 15 minutes prior to sampling.
  • Sample from a tap or spigot as close to the wellhead as possible, and prior to any treatment or filtration – see diagram.
  • Collect the sample into a labeled, unpreserved 250 mL plastic bottle supplied by Dellavalle Laboratory.
  • Label the sampling bottle with an indelible marker. Include the well ID, the samplers name, and the date and time the sample was collected.
  • Keep samples on ice in a cooler. Samples must arrive to the laboratory at a temperature of 4º deg C (39.2º F) or less.
  • Complete the Water Board Drinking Water Well Member Information form.
  • Complete the Dellavalle Laboratory work order form
  • Request NO3-N and NO2-N analysis.
  • Fill out the chain of custody on the work request form.
  • Submit the samples the same day they are collected.

Sample Delivery:

Samples may be dropped off at any of our office locations Monday-Thursday

Davis Office at 502 Mace Blvd, Suite 2B, Davis CA 95618 – Google Maps/Directions

Shipping samples to the laboratory

Samples may be shipped overnight to the Fresno Laboratory either by using the shipping method of your choice or via our courier service. Samples must be shipped in an ice chest with ice so that the samples arrives to the lab at a temperature 39.2º F or less. To schedule a courier pick-up, please contact the Fresno Office at 800-228-9896.

What to do if results are above 10 mg/L:

Meet Martin James

Meet Martin James

A Dellavalle Consultant

Our Consultants:
Over 40+ Years Experience
Serving California
3 Offices Statewide

Laboratory
  • 1910 W. McKinley Avenue, Suite 110, Fresno, CA 93728
  • (559) 233-6129
  • Mon - Fri 8am - 5:00pm
Consulting Offices

Davis Office

Hanford Office

Drop Off Locations

North County Copy & Parcel

Right Now Couriers

Get in Touch

  • (800) 228-9896

Privacy Policy | Accessibility Statement | ® Dellavalle Laboratory, Inc

Holiday schedule 2026 DELLAVALLE

Susan Villagran

Water Treatment Operator
T1

Susan attended San Joaquin Valley College where she earned an Associate of Science. She is a California Water Treatment Operator (T1) and a lead Sample Technician. Susan specializes in environmental monitoring including regulatory projects, drinking water systems and bacterial swabbing for packing sheds and other food processing industries. She serves clients throughout Kings, Tulare and Fresno counties.

Martin James

Environmental Specialist
D3/T2

Martin studied water treatment at Fresno City College and Sacramento State Water Programs. He has worked with drinking water systems since 2008 before joining Dellavalle in 2018. He specializes in environmental services and private/public water systems. Martin is a Distribution Operator (D3) and Treatment Operator (T2) serving Merced, Madera, Fresno, Kings, and Tulare counties.

Maribel Garcia

Food Safety Specialist
Office Administrator(Hanford)

Maribel attended Cal Poly, Pomona where she earned her bachelors in Microbiology with a minor in Chemistry. Maribel assists clients in the Tulare and Kings counties.

Cynthia Tiemersma

Dairy Technician

Cynthia was raised on her family’s dairy farm in Tulare County. She attended Dordt University where she graduated with a degree in Agriculture: Biotechnology. As a Dairy Technician for Dellavalle Lab, she assists dairy farmers with nutrient management, Dairy General Order regulations and requirements, and Comprehensive Nutrient Management Plans. Cynthia primarily works in Kings and Tulare Counties but also assists dairymen throughout the San Joaquin Valley.

Christian Duran

Agronomist
Technical Consultant(Fresno)

Christian is a certified crop advisor working as an Agronomic Support Tech with the Fresno Agronomy team. Born and raised in the Central Valley, he is no stranger to agriculture and the daily impact it has on rural farming communities. Christian obtained his B.S. in Plant Science from Fresno State and looks forward to servicing growers with their irrigation management, crop nutrition, and soil fertility needs.

Scotty Sakamoto

Agronomist

Scotty is a Certified Crop Advisor and works as an Agronomist for Dellavalle Lab. Born and raised in Clovis, California, he obtained a BS in Business Administration from Cal Poly San Luis Obispo along with an AA in Plant Science through Reedley College. Scotty services clients throughout Fresno, Madera, and Merced counties working with a diverse range of row and tree crops. Scotty’s journey in the world of agriculture is a testament to the fusion of business insight and agricultural stewardship. Whether you are a farmer seeking expert advice or an enthusiast eager to learn more about agriculture, Scotty is your go-to agronomist ready to share his knowledge and experience to help maximize yields while minimizing environmental impact.

Lisa Rubin

Agronomist
Technical Consultant

Lisa specializes in Regulatory Compliance. She works on Waste Discharge Requirement reporting, Sediment and Erosion Control Plans, Comprehensive Nutrient Management Plans, and many other permitting and compliance projects. Previously she worked at the State Water Board and has been with Dellavalle Lab since 2015. Lisa is a Certified Crop Advisor and Certified Technical Service Provider for CAP 102. In addition, she has a Bachelor’s in Plant Health Studies from Fresno State and an Associate’s in Natural Science and General Agriculture from Reedley College.

Chad Reenders

Manager
Agronomist

Chad studied Agricultural Engineering at Cal Poly San Luis Obispo. Prior to joining the Dellavalle Team, he gained valuable experience working on a farm that produced food and forage crops, as well as tree nuts. Chad has been a guest lecturer at Cal Poly, Cuesta, and Fresno State in soil and plant science classes. Chad is a Certified Crop Adviser serving Southern Fresno, Northern Tulare, Kings, San Luis Obispo, and Santa Barbara counties.

Carlos Olmedo

Agronomist
D1/T1

Carlos studied Agriculture at Woodland Community College and Business at CSU Sacramento. He has worked for Dellavalle Lab since 2012. He started as a Field Technician where he gained experience and studied to become a Certified Crop Adviser. Carlos is also a Distribution Operator (D1) and Treatment Operator (T1). He now serves both agricultural and environmental clients throughout Sacramento, San Joaquin, Stanislaus and surrounding counties.

Scott Fridlund

Principal
Lab Director

Scott has a Masters of Agricultural Chemistry from U.C. Davis. He worked in the Division of Agricultural and Natural Resources Lab prior to joining the Dellavalle Laboratory team in 1993.

Keith Backman

Sr. Agronomist

Keith has a Master’s degree in Horticulture/Pomology from U.C. Davis. He is also a Certified Crop Adviser, Certified Professional Horticulturist, and a California Water Distribution Operator. Keith has served as an expert witness for many Ag projects throughout the state and has vast lecturing experience for Universities and professional Associations and Conferences. He is also a contributing author for the Western Fertilizer Handbook and has been involved in the writing of Certified Crop Advisor Exams. Keith served as a Sr. Agronomist/Consultant for over 45 years and now offers his support and expertise to the rest of the Agronomy Team.

Danyal Kasapligil

Vice President
Secretary/Treasurer
Manager (Davis, CA)
Sr. Agronomist

Danyal received a BS in Plant Science from U.C. Davis, and an MS in Agriculture from Cal Poly. He has worked as a certified crop advisor for over 25 years and is also a certified professional agronomist, water system distribution operator (D-1) and a licensed pest control advisor. A past president of the California Irrigation Institute he currently serves on the advisory board for the western region certified crop advisors. Danyal manages our office in Davis and works with growers throughout northern California, providing assistance with plant nutrition, soil fertility, irrigation management, and soil site assessments for new developments.

Nat Dellavalle

Founder
Board Advisor
Soil Scientist
Sr. Agronomist

Nat is the Founder of Dellavalle Laboratory, Inc. He earned a Bachelor’s in Soil Science from Cal Poly. After graduation, Nat gained valuable on-farm experience prior to setting up several successful agricultural laboratories. He is a Certified Crop Adviser and Certified Professional Agronomist/Soil Scientist. Nat has served as President of the American Society of Agronomy -California Chapter, President of the Soil and Plant Analysis Council, and has served on many University, Agricultural and Environmental committees.

Ben Nydam

President
Sr. Agronomist

Ben is the President of Dellavalle Laboratory and has been with the company since 1990. He grew up on an almond farm near Turlock, CA and studied Agricultural Engineering at Cal Poly, San Luis Obispo. Ben is an irrigation specialist and a Certified Crop Advisor.

In addition, he is a past President of the American Society of Agronomy California Chapter and a member of the Technical Advisory Committee for the North Fork Kings Groundwater Sustainability Agency. As an Agronomist, Ben serves clients throughout Tulare and Kern counties.