N.H. Admin. Code § Env-Wq 1506.13

Current through Register No. 45, November 7, 2024

Section Env-Wq 1506.13 - Sediment Control Methods: Flocculants

(a) Flocculants shall only be used as specified in this section.

(b) Flocculants shall not be applied directly to or within 100 feet of any surface water of the state unless specifically approved by the department in writing in accordance with this section.

(c) The department shall not approve the use of flocculants unless the person requesting approval demonstrates that due to the presence of on-site clay colloidal particles, other erosion control measures, alone or in combination, will not be sufficient to prevent turbidity violations and sedimentation in downstream receiving waters.

(d) Sites shall be stabilized as soon as possible using conventional measures to minimize the need to use flocculants.

(e) A request for approval to use flocculants shall be submitted as soon as the need for such use is anticipated, whether with an application, while an application is pending, or after a permit has been issued.

(f) The applicant or permit holder, as applicable, shall submit the following for each type of flocculent proposed:

(1) Manufacturer's name;

(2) Product name;

(3) Material safety data sheets (MSDS) for the product;

(4) The results of chronic and acute toxicity testing of the product conducted in accordance with Env-Wq 1706.01 for wastewater;

(5) Proof from the manufacturer that the flocculants are anionic and certified for compliance with ANSI/NSF Standard 60 drinking water treatment standards;

(6) Certification by the applicant or permit holder, as applicable, that:

a. All proposed flocculants are the same as those used in the toxicity tests and will not be altered in any way for the project; and

b. No additional chemicals are needed or will be used to enhance performance of the flocculent;

(7) An explanation as to why conventional erosion control measures, alone or in combination, will not be sufficient to prevent turbidity violations and sedimentation in downstream receiving waters;

(8) A flocculant application plan as specified in (g), below, prepared in consultation with the flocculant manufacturer or authorized manufacturer's representative; and

(9) A water quality sampling plan as specified in (i), below, for all discharges treated with flocculants and all surface waters of the state receiving such discharges.

(g) The flocculant application plan required by (f)(8), above, shall include the following:

(1) A plan of the project showing where the flocculant will be applied and the name, location, and distance to all surface waters of the state immediately downstream that might receive discharge from areas treated with flocculants;

(2) The expected start and end dates for using flocculants, including a schedule and list of measures which will be taken to stabilize the site as soon as possible using conventional stabilization practices;

(3) Test results for representative soils from the site, and recommendations from the manufacturer based on the soil tests, indicating the type of flocculant and the recommended application rate;

(4) Frequency, method, and rates of application designed to ensure that flocculant concentrations will not exceed 50% of the IC25 or NOEC value, whichever is less, for the flocculant product used;

(5) Frequency of inspection and maintenance of the flocculant application system; and

(6) Method for the collection, removal, and disposal or stabilization of flocculated particles to prevent resuspension.

(h) Flocculant application systems shall be operated, inspected, and maintained only by qualified personnel with experience in the use of the type of system(s) being used.

(i) The water quality sampling plan required by (f)(9), above, shall include the following:

(1) At least 3 proposed water quality sample locations for each discharge and each receiving water, at least one of which shall be to establish background concentrations in the receiving water;

(2) The latitude and longitude of each sampling location in degrees, minutes, and seconds, with at least 3 decimal places of precision (DDMMSS.sss) and referenced to the North American Datum of 1983 (NAD 83) or its successor;

(3) For each piece of equipment used for water quality testing, the make, model, and accuracy of the equipment, subject to the following:

a. Turbidimeters shall have an accuracy of 0.05 or +/-2%, whichever is greater, for readings below 100 NTUs and +/- 3% above 100 NTUs; and

b. pH meters shall have an accuracy of +/- 0.2 pH units;

(4) Standard procedures for calibration and quality assurance;

(5) A sampling plan that meets the requirements of (j), below;

(6) A copy of the field data sheet that will be used that accommodates the collection of all data specified in (k), below;

(7) Contact information for each individual who will be conducting water quality sampling, including name, mailing address, and daytime telephone number, and, if available, an e-mail address and fax number; and

(8) The qualifications of each individual who will be conducting water quality sampling.

(j) The sampling plan required by (i)(5) shall require the following:

(1) All water quality sampling shall be conducted by qualified personnel with experience in water quality testing and analysis;

(2) For all parameters, one duplicate sample shall be taken as a quality control measure for every 10 samples taken;

(3) Unless otherwise approved by the department based on site-specific conditions, sampling for pH and turbidity shall be conducted:

a. In at least one stormwater discharge location prior to the application of flocculants;

b. In all treated discharges that discharge to a surface waterof the state at a point downstream of the area where flocculant has been applied but upstream of the receiving water;

c. In each receiving water at a point upstream of the area of the application of flocculants and at a point approximately 100 feet downstream of the confluence of the treated discharge and the receiving water;

d. For all wet weather events that produce a discharge; and

e. Every hour for the first 2 hours once a discharge commences, every 2 hours for the next 6 hours and every 8 hours thereafter until the discharge has ceased; and

(4) Information shall be provided regarding how the concentration of flocculant will be measured in each discharge that discharges to a surface water of the state to ensure that toxicity concentrations are not exceeded. If a surrogate parameter such as turbidity is proposed to meet this requirement, data shall be provided showing the relationship between the surrogate parameter concentration and the concentration of flocculant in the surface water.

(k) Sampling results shall include the date, time, sample location, value of the results, applicable water quality criteria, a summary of any violation(s) and actions taken to correct the violation(s).

(l) Whenever flocculants are used and a discharge occurs, the permit holder shall submit a summary report to the department on a weekly basis that includes the following:

(1) The type and quantity of flocculant used;

(2) The date, duration of discharge, and estimated discharge rate;

(3) The total volume of water treated;

(4) The concentration of flocculant in the discharge, with supporting calculations; and

(5) A comparison of the amount of flocculant used to that which was originally proposed in the approved flocculant application plan and an explanation for any deviations from the plan.

N.H. Admin. Code § Env-Wq 1506.13

(See Revision Note #1 at chapter heading for Env-Wq 1500) #9343, eff 1-1-09

Amended by Volume XXXVII Number 32, Filed August 10, 2017, Proposed by #12342, Effective 8/15/2017, Expires 8/15/2027.

Amended by Number 41, Filed October 12, 2023, Proposed by #13758, Effective 9/28/2023, Expires 9/28/2033 (see Revision Note #4 at chapter heading for Env-Wq 1500).